The pi/4 polyhedron

Matthias Goerner's 3D print: shpws.me/SZbN
Countdown d24: • From Sphericons to Cou...
Matthias' version of the construction of the polyhedron: www.unhyperboli...
Demonstration of the Wallace-Bolyai-Gerwien theorem by Dima Smirnov and Zivvy Epstein: dmsm.github.io...
Brooks and Matelski were the first to make an image of what we now call the Mandelbrot set. This image is in the public domain: en.wikipedia.o...
According to Wikipedia, Pingala studied the relations between the numbers in what we now call Pascal's triangle, but the first appearance of these numbers arranged in a triangle was due to the Persian mathematician Al-Karaji (953-1029).