Five regular skeletal polyhedra, c 1650-1691.
© Science Museum / Science & Society Picture Library
Skeletal polyhedra with inscribed stars, and their boxes. Since ancient times it has been known that there are only five regular polyhedra: three-dimensional figures which appear the same when viewed from any angle. This is the largest set asociated with the physicist Robert Boyle (1627-1691) and contains a tetrahedron, cube, octahedron, dodecahedron and icosahedron.