How many triangles are there in an n by n grid?

[@andreiraresboss1232]

Incredible video and well done made! I have learnt a lot from it. Thank you!

[@DrMcCrady]

Thank you for your kindness!

[@alexlensu6051]

incredible demonstration, thank you!

[@DrMcCrady]

Thank you for your kindness!

[@harrybetts8559]

For the 6 x 6 grid first shown at 7:20, how does your answer account for the straight line which contains the points (0,5), (1,3) and (2,1) for instance?

[@DrMcCrady]

Oh wow, thank you for pointing that out to me! My formula misses many of those types of segments, so I need to fix that.

[@brockobama257]

awesome video now do nxm

[@DrMcCrady]

Thank you, but I may have actually miscounted the degenerate triangles. Check out one of the earlier comments.