Affine-regular polygon properties of regular polygons are invariant under affine transformations, and affine-regular polygons share the same properties. For instance, an affine-regular quadrilateral can be equidissected into formula_1 equal-area triangles if and only if formula_1 is even, by affine invariance of equidissection and Monsky's theorem on equidissections of squares. More generally an formula_3-gon with formula_4 may be equidissected into formula_1 equal-area triangles if and only if formula_1 is a multiple of formula_3. Affine-regular polygon In geometry, an affine-regular polygon or affinely regular polygon is a polygon that is related to a regular polygon by an affine transformation. Affine transformations include translations, uniform
Hendecagram Hendecagram In geometry, a hendecagram (also endecagram or endekagram) is a star polygon that has eleven vertices. The name "hendecagram" combines a Greek numeral prefix, "hendeca-", with the Greek suffix "-gram". The "hendeca-" prefix derives from Greek ἕνδεκα (ἕν + δέκα, one + ten) meaning "eleven". The "-gram" suffix derives from γραμμῆς ("grammēs") meaning a line. There are four regular hendecagrams, which can be described by the notation Since 11 is prime, all hendecagrams are star polygons and not compound figures. As with all odd regular polygons and star polygons whose orders are not products of distinct Fermat primes, the