From Wikipedia, the free encyclopedia
A pentahedron (plural: pentahedra) is a polyhedron with five faces. There are two types:
- with a quadrilateral and four triangles as faces, i.e. a (regular or irregular) four-sided pyramid, such as the square pyramid
- with three pairwise adjacent quadrilateral faces and two non-adjacent triangular faces, e.g. a triangular prism, a triangular pyramidal frustum, or some other truncated triangular pyramid it has 7 sides 5 edges and 15 vertices.(i.e. one with the planes of the triangles non-parallel).