Soccer balls are usually covered with a design based on regular pentagons and hexagons.

How many pentagons/hexagons MUST there be, and why?

(In reply to Johnson solids by Jer)

I beg to differ.  Even a non-convex shape is still topologically equivalent to a sphere, just like the platonic solids, a soccer ball, or similar shapes.  (The point being that there are no holes in the surface.)

Posted by Thalamus on 2004-04-15 12:32:08