Книга: Pyramid (geometry): Geometry, Polyhedron, Polygon, Apex, Cone, Dual Polyhedron, Regular Polygon, Prismatoid, Regular Polyhedron, Tetrahedron

High Quality Content by WIKIPEDIA articles! In geometry, a pyramid is a polyhedron formed by connecting a polygonal base and a point, called the apex. Each base edge and apex form a triangle. It is a conic solid with polygonal base. An n-sided pyramid will have n + 1 vertices, n + 1 faces, and 2n edges. All pyramids are self-dual. When unspecified, the base is usually assumed to be square. If the base is a regular polygon and the apex is above the center of the polygon, an n-gonal pyramid will have Cnv symmetry. Pyramids are a subclass of the prismatoids.