A polygon is regular if it is uniform and its faces are all alike. The regular convex polyhedra are the five Platonic solids, which have been known since classical Greece. The ancient Greek ...

Besides the regular and semiregular solids, there are just ninety-two other convex polyhedra with regular faces. In 1966, the American mathematician Norman W. Johnson, a student of H.S.M. Coxeter at ...

A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles ...

In this way it is possible to follow the development of the disease, to see the crystal-like polyhedra as they are formed in situ and to observe the fine structure of their contents.