Soccer balls are usually covered with a design based on regular pentagons and hexagons.
How many pentagons/hexagons MUST there be, and why?
12 pentagons and 20 hexagons. I looked on my size 5 ball and a ball a lot smaller and there was 12 pentagons and 20 hexagons on both. But I'm not sure it has to be this way.
Edited on April 8, 2004, 3:41 pm