CUBE The cube is the only regular hexahedron and is one of the five Platonic solids . It has 6 faces, 12 edges, and 8 vertices. The cube is also a square parallelepiped , an equilateral cuboid and a right rhombohedron . It is a regular square prism in three orientations, and a trigonal trapezohedron in four orientations. The cube is dual to the octahedron . It has cubical or octahedral symmetry . The cube is the only convex polyhedron whose faces are all squares . PYRAMID A pyramid is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense . The base of a pyramid can be trilateral, quadrilateral, or of any polygon shape. As such, a pyramid has at least three outer triangular surfaces (at least four...
