Equiangular polygon Equiangular polygon In Euclidean geometry, an equiangular polygon is a polygon whose vertex angles are equal. If the lengths of the sides are also equal (that is, if it is also equilateral) then it is a regular polygon. Isogonal polygons are equiangular polygons which alternate two edge lengths. The only equiangular triangle is the equilateral triangle. Rectangles, including the square, are the only equiangular quadrilaterals (four-sided figures). For a convex equiangular "n"-gon each internal angle is 180(1-2/n)°; this is the "equiangular polygon theorem". Viviani's theorem holds for equiangular polygons: A rectangle (equiangular quadrilateral) with integer side lengths may be tiled
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