The reason the shape changes from 3D to 2D when you get to six triangles has to do with the number of degrees in an equilateral triangle. There are 60 degrees at each vertex of the triangle, so ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Pascal’s triangle is a never-ending equilateral triangle of numbers that follow a rule of ...

Henry Dudeney, a self-taught English mathematician and puzzle columnist, asked his readers to dissect an equilateral triangle into the smallest number of pieces that could be rearranged into a square.