The pyramid is kind of polyhedron. The base of pyramid is any polygon. Lateral faces are triangles. The right pyramid has regular polygon in base and its height drop directly onto center of the base. Lateral faces of regular pyramid are isosceles triangles. Volume: V = 1/3 * A_b * H. A_b - area of a base. H - height. Surface: S = A_b + A_l. A_l - lateral area (sum of areas of all lateral faces).