Geometrically the shape of C-60 fullerene is a truncated icosahedron. It's formed by starting with an icosahedron and slicing off each of the 12 vertices, leaving a pentagonal stump. The truncated icosahedron has two kinds of edges: pentagon-hexagon and hexagon-hexagon. Depending on where you make the cuts, one kind of edge can be longer than the other, or they can be the same length. in C-60 fullerene they are the same length.