A zonohedron is a convex polyhedron where every face is a polygon with point symmetry, or equivalently, symmetry under rotations through 180°. The regular polygons with such symmetry are those with an even number of sides, so the zonohedra with regular polygons for sides are easily enumerated:
Two other significant zonohedra occur amongst the duals of the Archimedean solids, these being the rhombic dodecahedron and the rhombic triacontahedron. The rhombic enneacontahedron, also is a zonohedron.
Mathematically, the zonohedra can be characterised as being the Minkowski sums of line segments, and this characterisation allows the definition to be generalised to higher dimensions, giving zonotopes.