Very few can solve this puzzle. How many squares?

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  • เผยแพร่เมื่อ 24 มิ.ย. 2024
  • How many squares can be made, using any 4 points as corners?
    0:00 problem
    0:30 solution
    3:24 animation
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ความคิดเห็น • 513

  • @globalincident694
    @globalincident694 หลายเดือนก่อน +179

    You don't need to check every set of four points. Since every square is uniquely defined by two opposing corners, you only need to check pairs of points. And you can also use the symmetries of the shape to save you some time.

    • @onradioactivewaves
      @onradioactivewaves หลายเดือนก่อน +13

      That's how I did it, it was pretty easy that way.

    • @teambellavsteamalice
      @teambellavsteamalice หลายเดือนก่อน +1

      Exactly

    • @vinching926
      @vinching926 หลายเดือนก่อน +6

      He just brute force every point combos for the sake of it

    • @qc1okay
      @qc1okay หลายเดือนก่อน +1

      Correct, just check all sets of two points, and keep a list of all squares already found so that when you get to the other diag of a square you've found the first diag of, you don't recount it. This video's idea of checking zillions of sets of four points, and then saying it's surprising no one ever did that, is silly. To check two points, simply see whether a 3rd point exists at the corresponding corner location, and if so, same for 4th point.

    • @gafjr
      @gafjr หลายเดือนก่อน +2

      Also, there's 4 quadrants. Whatever you get for one, multiply by 4. The only square that seems to repeat itself is dead center of the original 9. At least that's how I got it, (3*4) + 9. Of course it may have been a lucky guess.

  • @shoot_game718
    @shoot_game718 หลายเดือนก่อน +68

    I found all 9, of course, and also the 4 that are at odd angles. Somehow, I managed to find those ones while forgetting to check for the 45-degree rotated squares.

    • @jeremyashford2145
      @jeremyashford2145 หลายเดือนก่อน +2

      ditto

    • @MrDreugh
      @MrDreugh หลายเดือนก่อน

      Same here

    • @lucario5748
      @lucario5748 หลายเดือนก่อน +2

      I found the same ones you did, then played the video, and realized I missed the 45 degree ones about the same time he got to them.

    • @aukword6255
      @aukword6255 หลายเดือนก่อน

      Yup, me 2.

    • @the4spaceconstantstetraqua886
      @the4spaceconstantstetraqua886 หลายเดือนก่อน

      I missed the 4:3 triangles

  • @opinionhaver574
    @opinionhaver574 หลายเดือนก่อน +123

    I'm sure you named your algorithm animation "The Square Dance."

  • @mortoopz
    @mortoopz หลายเดือนก่อน +358

    So, only 1% of people consider rotated squares?... I find that hard to believe.
    [I'm not a crazy person, when posted this video was titled "Only 1% can solve" blah blah"]

    • @vetinaris1297
      @vetinaris1297 หลายเดือนก่อน +39

      Presumably 99% think rotated sqaures are diamonds or another shape so the brain doesn't look for it. That's my excuse anyway. At least this one doesn't feel like cheating 😂

    • @zlac
      @zlac หลายเดือนก่อน +105

      or they find 17 because they only search for 45° rotated squares

    • @jetx_47
      @jetx_47 หลายเดือนก่อน +17

      I’m in the 99% crowd.

    • @abhishankpaul
      @abhishankpaul หลายเดือนก่อน +3

      Me too dude. Tis hard to believe

    • @migssdz7287
      @migssdz7287 หลายเดือนก่อน +27

      ​@@zlacyeah I got 17. I actually thought of other rotations but for.some reason it seemed obvious to me that there couldn't be any square like this
      I am in the 99% :`(

  • @yippee8570
    @yippee8570 หลายเดือนก่อน +3

    I love the fact you wrote a program to affirm what you already figured out! I used to draw dots in various sized grids and join them in as many different ways as possible when I was a child. I think that was probably my first foray into probability.

  • @HopUpOutDaBed
    @HopUpOutDaBed หลายเดือนก่อน +20

    then there's me counting all the rotated squares, but then forgetting to count all of the 9 obvious cross squares other than the center.

    • @wiseoldfool
      @wiseoldfool หลายเดือนก่อน +1

      Don't you hate it when you over think things? I don't.

  • @staircase72
    @staircase72 หลายเดือนก่อน +14

    There is a more efficient brute force method than trying every single combination of 4 points. Once you have two ordered points, the other two points that would make up a clockwise oriented square. Assuming you take all ordered pairs of points and then check if the other points are valid, you will find all edges of all squares, or 4 times the number of squares with only n^2 tries (where n is the number of points we have). If you have a rule that lets you only try one side of each square, then you can do it in n^2/4 attempts.

  • @jucom756
    @jucom756 22 วันที่ผ่านมา +5

    You can mathematically prove there are only 21 squares by looking at the possible center points for the squares and using rotational symmetry to only have to check 8 center points, an then multiply the ones that aren't the very center by 4 to account for symmetry and you get 9 out of the under 40 center-vertex combinations that work and 5 of those with the epicenter so we have 5+4*4=21

    • @rorygilmoreNZ
      @rorygilmoreNZ 17 วันที่ผ่านมา +1

      well I’m surprised anyone would need to make a calculation at all. To me that seems ridiculously over worked. I got the the 9 square answer in about 5 seconds and the 21 square answer in about 30 just by looking at it and tilting my head. Just as a graphic artist might break down the elements of something you want to draw. It’s not a mathematical problem as much as a creative one. It’s just a question of visualisation surely… not intelligence.

  • @sidkemp4672
    @sidkemp4672 หลายเดือนก่อน +2

    Nicely done. Most often, you show a known solution or say you learned part of the solution from someone else. Clearly, this time, you found all 21 squares yourself and then validated it with a computational method. And, as always, excellent presentation. And your approach to both finding and explaining squares by creating right triangles and identifying side lengths to test was brilliant. Kudos!
    I did think of diagonal squares, but only found four of them. So I found 13 boxes in all. I thought my way out of the smallest box, but not out of the next box up.

  • @DigDug_The1975
    @DigDug_The1975 หลายเดือนก่อน +34

    Grrrrr. I paused this for almost 3 minutes and came up with 22. Soooo close. Great puzzle. Keep em coming with your brilliance on HOW to solve complex problems!

    • @ThePowerfulOne07
      @ThePowerfulOne07 หลายเดือนก่อน +4

      How does the 22th square look??? Which points did you use?

    • @nicknike
      @nicknike หลายเดือนก่อน +6

      22? I came up with 21 and I'm now playing the rest of the video. 😶

    • @The_Cali_Dude_88
      @The_Cali_Dude_88 หลายเดือนก่อน +1

      I got 20... rectangles aren't 'squares' and I told them that. True squares are equal all sides period🎉

    • @siliconslice
      @siliconslice หลายเดือนก่อน

      @@The_Cali_Dude_88 yes

    • @nicknike
      @nicknike หลายเดือนก่อน +3

      @@The_Cali_Dude_88 You can get 21 squares. Which one of them do you consider a rectangle?

  • @purplealarmclocker
    @purplealarmclocker หลายเดือนก่อน +6

    That animation was remarkably satisfying

  • @krzysztof_jablonski
    @krzysztof_jablonski หลายเดือนก่อน +2

    My initial guess is 21, but instead of lengths like you do in the video I select a vector which is the first side of a square (select a point as 1st vertex, add the vector to get a 2nd vertex, add the vector rotated 90° to get the 3rd vertex, then add the vector rotated 180° to get the 4th vertex; all 4 form a square, you get the idea). Since the dots can be placed on discrete two dimensional grid of size 6x6 there's only a handful of vectors to choose from. Since the square has a rotational symmetry of order 4 we can consider only vectors with both coordinates being non-negative integers (Quadrant I) and still miss no cases.
    Here's my dissection of possible first square side vectors along with the number of dots that would form a square with all 4 vertices lying on the dots:
    (0,1) - 9
    (1,1) - 4
    (2,2) - 4
    (1,2) - 1
    (2,1) - 1
    (2,3) - 1
    (3,2) - 1
    I believe it could be easier to program with this approach, as you wouldn't have to check if the 4 points combination forms a square, but instead given a square verify if all it's vertices belongs to a set of points provided as input. Also it would decrease the computational complexity, because there's only 35 such vectors possible in a 6x6 grid (plus a trivial (0,0) vector but those squares don't count) and check all of them against every one of the 20 points you only have 700 cases to run. That's already significantly lower than C(20,4).
    The number can be further shaved down if discard the vectors that are available in a full 6x6 grid but not in the input set. It can be easily proved visually, that for first coordinate of [number on the left] the second coordinate can only go as high as [number on the right]:
    0, 5
    1, 5
    2, 3
    3, 3
    4, 1
    5, 1
    Considering only vectors of
    (0,1) through (0,5) // skipping the trivial (0,0) for the total of 5
    (1,0) through (1,5) // 6
    (2,0) through (2,3) // 4
    (3,0) through (3,3) // 4
    (4,0) through (4,1) // 2
    (5,0) through (5,1) // 2
    we get the grand total of 23 vectors to check against 20 points for 460 combinations. Over 10x less than C(20,4).

  • @aleksandersaski5387
    @aleksandersaski5387 หลายเดือนก่อน +4

    Nailed it!

  • @DrCeeVee
    @DrCeeVee 9 วันที่ผ่านมา +2

    I did the same as in the video, and came up with 21 squares, but also wanted to brute-force it, just in case. I wrote a simple MATLAB code that tests all 4845 combinations. For each combination, all squared distances are computed, and then sorted and duplicates removed, thus forming a "set" of distances. Those sets with a cardinality of 2 (i.e., the square's side and diagonal lengths) correspond to perfect squares. The answer was 21 squares. MATLAB code below. At the end of execution, variable n contains the answer.
    clear variables
    P = [2,0;3,0;2,1;3,1;0,2;1,2;2,2;3,2;4,2;5,2;0,3;1,3;2,3;3,3;4,3;5,3;2,4;3,4;2,5;3,5];
    C = nchoosek(1:size(P,1),4);
    n = 0;
    for i = 1:size(C,1)
    d = [];
    for j = 1:4
    for k = j+1:4
    d = [d;(P(C(i,j),1)-P(C(i,k),1))^2+(P(C(i,j),2)-P(C(i,k),2))^2];
    end
    end
    d = unique(d);
    if length(d) == 2, n = n+1; end
    end

  • @johnlawrence7386
    @johnlawrence7386 18 วันที่ผ่านมา

    I was listening to an audiobook and using another tab to see what was on YT, I came across this video and thought it was interesting. Surprisingly I came up with the answer.

  • @strangebird5974
    @strangebird5974 หลายเดือนก่อน +3

    The more interesting question would be how to form a concise proof that there are only 21 possible squares to construct. I would start by noting that, apart from repeating pattern and mirroring, there are only 3 distinct "kinds" of dots in the pattern (the dot closest to the middle, the dot one out from the middle and the dot furthest away from the middle). Thus, we would only need to show the exhaustive number of kinds of squares with each of these 3 dots as a corner. That is pretty doable.

    • @MichaelRothwell1
      @MichaelRothwell1 หลายเดือนก่อน +1

      That is my question too. Someone already pointed out that a square is defined by its opposite corners, so you only have to consider pairs of points, then simplify further using the symmetry of the shape.

  • @WhiteGandalfs
    @WhiteGandalfs หลายเดือนก่อน

    That was one of the first computer games we made ourselves on a "home computer" at college, using a version that accepted only straight squares as template and generalizing it to arbitrarily positioned squares - 40 years ago. Was a nice exercise for the introduction into 2D vectors. Nostalgie :D

  • @RobShawGB
    @RobShawGB หลายเดือนก่อน +2

    It would be interesting to know if there is a general rule here for shaped like this. If this was considered of order 2, an order of 3 equivalent would be made up of five 3x3 squares. Or even look at cubes in a 3d version?!

  • @OneTrueBadShoe
    @OneTrueBadShoe หลายเดือนก่อน

    I made use of the symmetry. I graphed them and put the origin of the cartesian plane in the center. I only check to see if there is a side between (1,y) quadrant 1 and points within (-y,y) if that makes sense.
    I check
    (1,1) to (-1,1) is the side of a square. The diagonal passes through the center, so I count 1 square
    (1,2) to (-1,1) is a side. The diagonal does not cross through the center, I count 4
    (1,2) to (-2,1) is a side. The diagonal crosses through the center. I count 2
    (1,2) to (-1,2) is a side. The diagonal does not cross through the center. I count 4.
    (1,3) to (-1,1) is not a side
    (1,3) to (-2,1) is a side. The diagonal does not cross through the center, I count 4
    (1,3) to (-3,1) is a side, The diagonal crosses through the center, I count 2
    (1,3) to (-1,2) is not a side
    (1,3) to (-1,3) is a side. The diagonal does not cross through the center. I count 4
    Total of 21

  • @pieffe8
    @pieffe8 หลายเดือนก่อน

    In the automated counting of the squares, instead of considering each choice of 4 points, I'd have selected only 2 as two consecutive vertices of a square in clockwise order. At this point you can compute the coordinates of the other two vertices and see if they are valid. (You can find the third and fourth vertices by taking the vector between the two first vertices, rotate it 90 degrees clockwise, and apply it to the first and second vertices.) You can remove duplicates by only considering vectors going "right" (increasing x), and whose y coordinate doesn't decrease.

  • @keeplearning6
    @keeplearning6 23 วันที่ผ่านมา

    Thank you for making this video. Just wanted to know which language/tool you used to program the possibilities. It would be great if you can share the code as well.

  • @hafez591
    @hafez591 หลายเดือนก่อน

    Great that you could computationally check all of the possibilities!👍

    • @randombrian256
      @randombrian256 หลายเดือนก่อน

      Yes but I think he only checked combinations when he should have checked permutations just to be sure! 😄

  • @r.j.d3923
    @r.j.d3923 หลายเดือนก่อน +2

    I think it is at least 30 squares:
    Look at @2:14 and @2:54; both solutions you made use of the dots as cornerpoints, but 4 additional small squares occur when you draw the 4 squares.
    So by drawing 21 squares you get 30 squares. Maybe I overlooked some more?

    • @s3m527
      @s3m527 หลายเดือนก่อน +3

      Yeah, but those small squares are not connected to a point on each corner 🤓

  • @TuSkoFskY
    @TuSkoFskY หลายเดือนก่อน

    Hi Presh! I was wondering if you gave a thoutgh about the numbers in which correct combinations are occuring? Are they forming any pattern? For sure it depends on the shape of points on the lattice. But maybe there is some regularity behind that? Would be nice to make another use of that algorithm :)

  • @dylan9013
    @dylan9013 หลายเดือนก่อน +1

    I haven't done a problem like this since I've been in college (I graduated seven years ago), so I'm pleasantly surprised I solved this one with ease. I found the 1 squares first, followed by the root 2 squares, then the root 13 squares, then the root 5 squares, and lastly the 2 root 2 squares. I had no math behind it. I just visualized it!

    • @RobiBue
      @RobiBue หลายเดือนก่อน +1

      I love to do these problems. This one didn’t take math but noting which squares were already counted. Got all 21 but did it on paper with 3 patterns for the different angles.

    • @Tiqerboy
      @Tiqerboy หลายเดือนก่อน +1

      I could NOT visualize ALL the tilted squares without tracing them out. My mind was going numb trying to trace them out on the grid and then keep track of them. I had to methodically draw them all out to get the right answer. This is true for problem solving in general. I have to put pen to paper. I run into trouble if I try to do anything complex like this in my head.

    • @dylan9013
      @dylan9013 หลายเดือนก่อน

      @@Tiqerboy But you still got the right answer! That's what matters!

    • @dylan9013
      @dylan9013 หลายเดือนก่อน

      @@RobiBue Very nice!

  • @FirasFaleh-oj2ex
    @FirasFaleh-oj2ex หลายเดือนก่อน +1

    Can you make a video about this problem:
    Let ABC be a triangle and M be a point inside it
    1) let a, b and c be three strictly positive real numbers
    we put:
    x=(a+b)/c, y=(b+c)/a, z=(c+a)/b
    check that xyz=x+y+z+2
    2) the lines (AM), (BM) and (CM) intersect respectively at A', B' and C':
    to show that:
    (MA/MA') • (MB/MB')
    • (MC/MC') = MA/MA' + MB/MB' + MC/MC' + 2

  • @Anti_Woke
    @Anti_Woke หลายเดือนก่อน

    Programing always turns out to be harder than expected. Good job.

  • @laurenmilson7102
    @laurenmilson7102 หลายเดือนก่อน

    This was super interesting 👍 thanks

  • @JamesWanders
    @JamesWanders หลายเดือนก่อน

    With your code, you could also tally rectangles, kites, rhombi, trapezoids, parallelograms etc... be interesting to see how they compare.

  • @cmuller1441
    @cmuller1441 หลายเดือนก่อน +1

    Instead of trying all 4 points, you can just test all pairs with the first point being higher or more left than the second and test if the 2 remaining points for a square (clockwise travel) are in the set.

  • @ToBeUs_ToniBeranger
    @ToBeUs_ToniBeranger 24 วันที่ผ่านมา

    Maybe the first time I was able to figure out the correct answer of one of your problems without any help!
    I'm pretty good in mathematics and also help students with that, but nevertheless I can still learn very much from your videos, thx therefore! :D

  • @rohitchakra9280
    @rohitchakra9280 หลายเดือนก่อน

    I am impressed by the animation; how to generate? any suggestions?

  • @davebashford3753
    @davebashford3753 หลายเดือนก่อน

    I'm curious how you tested for or sorted for "non-intersecting polygons" [3:56] and is that the same as convex polygons? Some 20+ years ago, we had regular terrain data points that required 2 triangles for each 4 points to render. I tried to optimize the terrain into fewer points, but got stuck on the test/sort that you solved. A short description or pointer would be appreciated.

  • @eliechaya9690
    @eliechaya9690 หลายเดือนก่อน

    I like that your title is so different of the actual question discussed

  • @perekman3570
    @perekman3570 หลายเดือนก่อน +2

    May i ask what software/library was used to do the animation and render the video?

    • @cheweh842
      @cheweh842 หลายเดือนก่อน +1

      Looks like 3b1b/manim

  • @pramodsingh7569
    @pramodsingh7569 หลายเดือนก่อน

    Thanks

  • @Shirazmatas
    @Shirazmatas หลายเดือนก่อน

    How would you solve it if the question asked for how many rectangles rather than squares, is there a way without just computing?

  • @hippophile
    @hippophile หลายเดือนก่อน +1

    I got this. So I am in the putative 1%. Really it just requires care and probably helps to have seen something vaguely similar to find the skew ones. I find it hard to believe it is only 1% of us though, there wasn't anything really surprising there. Double counting was the main thing I found I needed to avoid... book-keeping skill...

  • @warny1978
    @warny1978 หลายเดือนก่อน

    There's an optimisation for your algorithm.
    Once you have choosen 2 points, which can't be horizontally aligned, you can consider it is the side of the square abd that you'll only search far squares that are on right and bottom of your 2 points. If the square missing vertices matches two points, you have found a new square. You'll find all squares with less tests.

  • @The_Commandblock
    @The_Commandblock หลายเดือนก่อน +3

    Thank you for making me feel smart lol

  • @marvhollingworth663
    @marvhollingworth663 หลายเดือนก่อน

    Nice, I got it right! I was about to declare 9 as my answer, but then thought "Hang on, what about diagonals?" Went for 21 but expected him to keep going beyond 21 with some I missed. Was really pleased when he didn't.

  • @pierreardouin6441
    @pierreardouin6441 หลายเดือนก่อน

    There are fundamentally 3 different types of points. Type A (8 points) belong to 3 squares, Type B (8 points) belong to 5 squares and type C (4 points) to 5. So thz number of squares is (8×3 + 8×5 + 4×5)÷4 = 21.

  • @smylesg
    @smylesg หลายเดือนก่อน

    4:51 I wish when the music started, he played a different tone for each point touched. He found enhance it by leaving the initial points playing while looking for the other possibilities.

  • @hrk992
    @hrk992 6 วันที่ผ่านมา

    To solve the problem computationally, I think you can avoid ordering the points to form a non-intersecting polygon by computing the distances between every possible pair of points and storing the values that are unique, if the shape form a square there should only be two unique distances (side and hypotenuse) otherwise that won't be the case

  • @noelwest8234
    @noelwest8234 หลายเดือนก่อน

    My first count was 10, but I had a feeling there were more. I just could not see them. Thanks for the early morning headache.

  • @robdielemans9189
    @robdielemans9189 หลายเดือนก่อน

    I missed 2 of them. great video!

  • @wilhelmmeyer89
    @wilhelmmeyer89 6 วันที่ผ่านมา

    Very nice!

  • @EugeneMayevski
    @EugeneMayevski หลายเดือนก่อน

    I found all the squares easily, but to me, the text is a bit vague. When a square must use four points at corners, does this mean that it may or may not have other points on its sides? I read the text the way that it may not (and then some of the found squares must be excluded).

  • @Toztabud
    @Toztabud หลายเดือนก่อน

    What tune is that at 5:00? I recognise it. Is it Tetris or Snake or something?

  • @chandranisahanone
    @chandranisahanone หลายเดือนก่อน +3

    I am following u since 3years , and I am totally obsessed by your ability of solving any problem, U are great 👑👑👑👑

    • @douglaswolfen7820
      @douglaswolfen7820 หลายเดือนก่อน +1

      Ah, but you've got a logical fallacy there. We don't know that he can solve every problem
      For all we know, he only solves one out of every ten problems he finds. He just doesn't make videos about the other nine

    • @chandranisahanone
      @chandranisahanone หลายเดือนก่อน

      @@douglaswolfen7820 No matter what he does but he is the goat!

  • @daboffey
    @daboffey หลายเดือนก่อน

    A more efficient way of counting would be choosing two points at a time and checking whether a square with them as opposite corners is on the grid. Then divide by two, as the squares would be double counted.

  • @doranchak
    @doranchak 26 วันที่ผ่านมา

    What do you use to make these animations? (You probably get asked this a lot - sorry!)

  • @Patrik6920
    @Patrik6920 หลายเดือนก่อน

    actually, thers atleast 23 as the question is asked,
    if u draw lines trom the outer most points
    nr 22:
    L upper point- down to R 45 deg edge point
    R upper point- down to L 45 deg edge point
    L lower point - upp to R 45 deq edge point
    R lower point -to- upp L 45 deg edge point
    ..the resulting squere will have a side of 2(√2) units, and a starting point 0.5 units from the edges
    nr 23: a smaller one one step in with the side √2
    ..cant atm see any more...

  • @antoinedragnir142
    @antoinedragnir142 หลายเดือนก่อน

    I didn't see the last two squares.
    Nice problem !
    I guess we could also consider more points to create an harder question.

  • @panlomito
    @panlomito หลายเดือนก่อน

    I first did it on paper but opened AutoCad that will provide distances between points. That was much easier and probably the 1% having the right tools to solve this challenge.

  • @sweepingpage1845
    @sweepingpage1845 หลายเดือนก่อน

    If you don't restrict it to requiring the points be the corners, you can draw 9 more squares that form from intersecting lines.

  • @timetraveller6643
    @timetraveller6643 หลายเดือนก่อน

    I want a measuring rod 100 cm long with every integer distance marked, but with the minimum number of marks. I can do this with a six cm rod (A,D) in only two marks, one cm from the bottom (B) and two cm from the top (C). This gives all six integer lengths in total.
    AB =1, CD=2, BC=3, AC=4, BD=5, AD=6.
    What is the minimum number of pencil marks on any rod that includes every integer measurement? How are the marks arranged? As the increments are increased, do we approach a well known geometric series?

  • @WRSomsky
    @WRSomsky หลายเดือนก่อน

    I would have left the 2*Sqrt(2) as the "improper" Sqrt(8) Makes the progression more evident.

  • @viliamholub509
    @viliamholub509 หลายเดือนก่อน

    Note you can remove all cases where three dots (corners) stay on single a line.

  • @user-ed1ty6nq7w
    @user-ed1ty6nq7w 20 วันที่ผ่านมา

    Wouldnt be checking pairs of points enough? Still it would give you repeats, but it would be easy to find, and no concaves would be generated?

  • @kylaxial
    @kylaxial หลายเดือนก่อน

    I came up with 9, then paused the video shortly after the explanation started, because I had remembered diagonal squares. I counted 21, but I miscounted 2 more odd angle ones and missed 2 45 degree angle ones.

  • @romain.guillaume
    @romain.guillaume หลายเดือนก่อน

    I got it. I just search for every possible side lengths :
    9 of 1
    Sqrt(2) and 2sqrt(2) (45°) are basically the same at a scale factor with 4 squares each
    Same for sqrt(5) and sqrt(13) with only 2 each

  • @ricks7469
    @ricks7469 24 วันที่ผ่านมา

    There are 21. If you number the dots from top to bottom, left to right; there are 9 like 1:3:4:2, 4 like 4:7:14:9, 4 like 3:12:18:9, 2 like 2:6:18:10, and 2 like 1:9:20:8.

  • @Inspirator_AG112
    @Inspirator_AG112 หลายเดือนก่อน +1

    I counted 21, after looking for all possible ways to create squares connect-the-dots-style with the points given.

    • @mattc3581
      @mattc3581 หลายเดือนก่อน +1

      Indeed takes about 30 secs at most to count them all, so anything more than counting is a little overkill unless you don't feel confident in picking out all the different types.

  • @Thorsten.Youtube
    @Thorsten.Youtube 25 วันที่ผ่านมา

    Yeah, took me some thinking but paused the video at 0:20 and found 21 without difficulty, seriously I found it pretty easy, albeit interesting.

  • @sintaxera
    @sintaxera หลายเดือนก่อน +1

    I found them in about 15 seconds, thought I was missing something. I didnt even watch the video, just from the thumbnail 😂

  • @MateusMuila
    @MateusMuila หลายเดือนก่อน

    Only 1% could solve it indeed , thanks for sharing your knowledge Sir.

  • @bigolbearthejammydodger6527
    @bigolbearthejammydodger6527 หลายเดือนก่อน

    FIRST QUICK PASS before video( I missed the 1 x 2 angle and 1 x 3 angle...DAMN MY OLD SLOW BRAIN!)
    however....
    If you assume a isometric(non perspective) 3d space - you can make a 3d view of a cube.. which has 6 squares, with 3 of them hidden!(+replicate for view angles) I think you can even connect lines to form a hypercube.. Im still trying that. Your algorithm help me work this out so credit where its due. Not sure if this has broken the puzzle record with this as I suspect its outside of the intended (but not stated) parameters.
    If I'm right - follow up vid Presh? Did I break the record? (with your help)
    Edit: Thinking on this idea further...
    if you allow for perspective ratios of 1/1, 1/2 and 1/3 and 1/infinite you can make many many more cubes - each with 2 or 3 visible faces and the rest hidden.
    perhaps this is a rabbit hole best avoided?

  • @3characterhandlerequired
    @3characterhandlerequired หลายเดือนก่อน

    I found all of them quite quickly in just few minutes, but I didn't trust that I have found them all and also thought that I might have counted few multiple times.

  • @alexharkler
    @alexharkler หลายเดือนก่อน

    guessing before watching. I got 21. 9 trivial small. 4 small at 45deg, 4 large at 45deg, and 4 centered using the outer 4 dots with radial symmetry

  • @paulrandig
    @paulrandig หลายเดือนก่อน

    It is kind of satisfying but also an overkill to check ALL combinations.
    It would be simpler to have two points and add a third point.
    IF the distance 1-2 is not equal to the distance 2-3, there cannot be a square.
    IF the distance 1-2 is equal but the lines do not form a right angle, there cannot be a square.
    Only if those two conditions do apply, you have to check a 4th point at all.
    BUT: It would be very interesting what the average area of all those polygons is and other statistics like the lenghth of all lines and so on.

  • @billbucktube
    @billbucktube หลายเดือนก่อน

    Like it‼️

  • @gm2407
    @gm2407 หลายเดือนก่อน

    Finally, one I got the answer first time.

  • @jiahao2709
    @jiahao2709 14 วันที่ผ่านมา

    may i know how you make these animation videos?

  • @rapid13
    @rapid13 หลายเดือนก่อน

    As soon as you used the magic word "any" I knew there'd be way more than 9 lol!

  • @Valdagast
    @Valdagast หลายเดือนก่อน

    How many isosceles triangles can you form?

  • @bakrantz
    @bakrantz หลายเดือนก่อน

    Finding the total number of rectangles would be interesting as well.

  • @ccost
    @ccost หลายเดือนก่อน +1

    i also could only find 17, i considered the non 45 degree squares but didnt find any as i expected there to be 4 not 2 hence me ruling it out too early

    • @gwiyomikim5988
      @gwiyomikim5988 หลายเดือนก่อน

      I got 17 as well before being distracted by a notification for a new cat video!🐈🐈‍⬛

  • @clonefighter1996
    @clonefighter1996 หลายเดือนก่อน

    I missed 8 of the trivial squares... these types of things sure can mix you up

  • @sonicwaveinfinitymiddwelle8555
    @sonicwaveinfinitymiddwelle8555 18 วันที่ผ่านมา +1

    I can't be the only one who counted all 13 rotated squares and forgot to count in also the 9 simple squares.

  • @gwiyomikim5988
    @gwiyomikim5988 หลายเดือนก่อน +2

    In 1893 they found only 17 because they had other problems to solve like where they’d get their next meal, or how to survive the latest cholera, smallpox, typhus, or yellow fever outbreak.😉

  • @kilroy987
    @kilroy987 หลายเดือนก่อน

    I found the easy 9 and the diagonal 4. I didn't realize how many more there were.

  • @former-time-trio_fan
    @former-time-trio_fan หลายเดือนก่อน

    before watching i tried solve this by myself, and got the right answer

  • @thesushifiend
    @thesushifiend 9 วันที่ผ่านมา

    You don’t need computational power when you have logic.

  • @user-or5ke5yn4w
    @user-or5ke5yn4w หลายเดือนก่อน

    Got it right, pretty easy.

  • @turtletom8383
    @turtletom8383 หลายเดือนก่อน

    Is their a reason you cant connect a few of those middle squares to make cubes and count the other faces as squares?

    • @velvetbutterfly
      @velvetbutterfly หลายเดือนก่อน

      You can't make a cube with 4 points

    • @turtletom8383
      @turtletom8383 หลายเดือนก่อน

      ​@@velvetbutterflyyeah it says how many squares can be drawn using any four corners if you draw a cube there is a square on the side drawn using four corners just not on the same plane

  • @MichaelPaoli
    @MichaelPaoli หลายเดือนก่อน

    How many squares using any four points?
    Would be sum of all the squares using any four points.
    So, let's sum them up.
    We'll only count each square once for any given set of four points.
    Let's start with smallest integral side length squares and go up from
    there.
    For reference, let's label each point,
    we'll use a Cartesian-like reference, similar to (x,y),
    but for brevity we'll omit all but xy, so instead of,
    e.g. (2,1) we'll just use 21.
    We'll label the points as follows,
    with x ranging from 0 through 5, all integers, and likewise for
    y, so, these are the labels for our points, shown graphically to
    correlate to their positions (and - for unfilled space/points):
    ------52-53------
    ------42-43------
    30-31-32-33-34-35
    20-21-22-23-24-25
    ------12-13------
    ------02-03------
    So, smallest squares have side 1, and there are
    9 of those.
    We have no squares of integral side lengths of 2 through 5 nor larger,
    nor smaller than 1, so what about other sizes between?
    Sides of (square) root 2 ... we have
    4 of those (may be easier to visualize by rotating image 90 degrees).
    Sides of (square) root 5? ... again, rotating may aid visualization,
    and we have ...
    2 of those (don't forget both non-redundant rotation sets).
    Sides of 2 root 2? ...
    4 of those (think of these,
    squares having adjacent corners 02 and 20 x 4 for symmetry = 4,
    each consumes a pair of the most extreme horizontal (x) and
    vertical (y) points, and there are only 8 of those to consume, so that
    gives us our 4 squares of 2 root 2 sides.
    )
    Next side size we can consider is root(2*2+3*3)=root 13 ...
    2 of those only and exactly, due to what fits + symmetry/rotation
    Next we have side size 3 root 2,
    ... and we don't have anything that size or larger that fits all four
    square sides.
    So, add 'em up, 9+4+2+4+2=
    21 squares.

  • @androart1817
    @androart1817 6 วันที่ผ่านมา

    I got the 1st and 5th type of square before clicking the video and then the 2nd before the explanation. Probably could’ve got the rest with time and a pen

  • @ianhoskins4455
    @ianhoskins4455 หลายเดือนก่อน

    Haven’t read through all comments yet but it seems this can be reduced using some geometric properties of squares.

  • @peterrombouts2271
    @peterrombouts2271 หลายเดือนก่อน

    How many for the 3D equivalent?

  • @Narikvp
    @Narikvp หลายเดือนก่อน

    I only found 17. Missed the four squares that don’t have a point in the center of each side ( sqrt 5 and sqrt 13).

  • @abhishankpaul
    @abhishankpaul หลายเดือนก่อน

    So you are saying that people did not consider rotated squares?

  • @Pocketfarmer1
    @Pocketfarmer1 หลายเดือนก่อน

    It could be argued that the four 2√2 are not legitimate for the problem because their side pass through another of the given points. None of the other squares do this. If the problem is to make squares from one point to a second ,then the 2√2 lines stop before completing the square . So 17 would be the right answer.

    • @leoc.9341
      @leoc.9341 หลายเดือนก่อน

      That is the answer I got for the very same reason.

  • @aukword6255
    @aukword6255 หลายเดือนก่อน +1

    Arguably, there are actually 84 possible squares. As humans, we just naturally tend to collapse the 4 different starting points for each square down to a single solution. A machine would consider them distinct.

    • @adamperdue3178
      @adamperdue3178 หลายเดือนก่อน +1

      Just because a machine would say so, doesn't make the machine correct. If I look at my house from a different angle, it isn't a new house.

    • @aukword6255
      @aukword6255 หลายเดือนก่อน +1

      @@adamperdue3178 Reasonable, it's just a matter of definition. It's not a new house, but it is a new VIEW of a house.
      Every entity must operate on what IT considers an important instance. There are also cases in human endeavour where the starting corner is important.

  • @veteran501
    @veteran501 14 วันที่ผ่านมา

    hehe a good one! i counted 17 but got sloppy and didnt count the sqrt(5) and sqrt(13)... nice one :)

  • @rustybarrel516
    @rustybarrel516 หลายเดือนก่อน

    I GOT ONE!!! I don’t BELIEVE it! This is better than the day the new phone book arrived! (But not as good as the day I discovered my special purpose).

  • @pabeader1941
    @pabeader1941 29 วันที่ผ่านมา

    I didn't allow 2square root of 2. It has other intersecting dots which I didn't allow.

  • @BryzArts
    @BryzArts หลายเดือนก่อน

    wow a design question..... its from uceed, a design examination in india

  • @user-km1cf1gs8x
    @user-km1cf1gs8x หลายเดือนก่อน

    I fell short at 19 !?!?
    I’ll forever be haunted by those 2 Squares Short 😮

  • @bradleyjohnenright7017
    @bradleyjohnenright7017 2 วันที่ผ่านมา

    So this is what a square on acid dancing looks like 🤣