Regular polygon common angle is a constructible number—that is, can be written in terms of the four basic arithmetic operations and the extraction of square roots. A "regular skew polygon" in 3-space can be seen as nonplanar paths zig-zagging between two parallel planes, defined as the side-edges of a uniform antiprism. All edges and internal angles are equal. More generally "regular skew polygons" can be defined in "n"-space. Examples include the Petrie polygons, polygonal paths of edges that divide a regular polytope into two halves, and seen as a regular polygon in orthogonal projection. In the infinite limit "regular skew polygons" become
Frustum volume of a pyramidal frustum whose bases are "n"-sided regular polygons is where "a" and "a" are the sides of the two bases. For a right circular conical frustum and where "r" and "r" are the base and top radii respectively, and "s" is the slant height of the frustum. The surface area of a right frustum whose bases are similar regular "n"-sided polygons is where "a" and "a" are the sides of the two bases. Frustum In geometry, a frustum (plural: "frusta" or "frustums") is the portion of a solid (normally a cone or pyramid) that lies between one