Noun
The word is derived from polyhedron
of Polyhedron
Source: Webster's dictionaryA concave bipyramid has a concave interior polygon. : The face-transitive regular bipyramids are the dual polyhedra of the uniform prisms and will generally have isosceles triangle faces. Source: Internet
A complex polyhedron is mathematically more closely related to configurations than to real polyhedra. Source: Internet
Alexander Borisov, Mark Dickinson, and Stuart Hastings, "A congruence problem for polyhedra", American Mathematical Monthly 117, March 2010, pp. 232-249. Source: Internet
Altogether there are nine regular polyhedra. Source: Internet
Aside from a rectangular box, orthogonal polyhedra are nonconvex. Source: Internet
Besides the regular polyhedra, there are many other examples. Source: Internet