well, it gets tricky, so I'll let Bosch explain it: Their 120-sided polyhedron has 12 vertices where 10 triangles meet. Henry and Robert wanted the numbers on the 10 faces that surround a vertex ...

It is possible that the polyhedron’s vertices would all coincide with points on a sphere, and in fact there are drawings in a Dürer sketchbook that suggest this possibility. What’s more ...

The vertices of a pyramid are around the polygon ... Platonic solids close platonic solidA polyhedron with regular polygon faces. These are the tetrahedron, cube, octahedron, dodecahedron and ...