A polyhedron having six quadrilateral faces. A cube is an equilateral hexahedron, as well as being a prismatoid. The regular hexahedron is one of the five Platonic solids (along with the tetrahedron, octahedron, dodecahedron, and icosahedron). The plural form can be either hexahedrons or hexahedra.Also see mathematics, polygon, and vertex.