Polyhedra

A polyhedron is such a body whose surface consists of a finite number of flat polygons.

A polyhedron is said to be convex if it is located on one side of the plane of each flat polygon on its surface. The common part of such a plane and the surface of a convex polyhedron is called a face . The faces of a convex polyhedron are flat convex polygons. The sides of the faces are called the edges of the polyhedron , and the vertices are the vertices of the polyhedron .

The simplest polyhedra: cube, prism, pyramid.