Named for Plato, who theorized that the classical elements were made of these regular polyhedrons, three of the Platonic solids are composed of equilateral triangles: the tetrahedron, octahedron, and ...
Counting will get you nowhere. Try a little combinatorics instead. By Kenneth Chang A couple of weeks ago, I wrote about a viral math problem — 8÷2(2+2) = ? — that drew the disdain of many ...