Dual polygon  From Wikipedia, the free encyclopedia Jump to:
navigation, search  In geometry, polygons are associated into
pairs called duals, where the vertices of one correspond to the
edges of the other.   Dorman Luke construction, showing a
rhombus face being dual to a rectangle vertex figure.  Regular
polygons are self-dual.  The dual of an isogonal (vertex-
transitive) polygon is an isotoxal (edge-transitive) polygon.
For example, the (isogonal) rectangle and (isotoxal) rhombus are
duals.  In a cyclic polygon, longer sides correspond to larger
exterior angles in the dual (a tangential polygon), and shorter
sides to smaller angles.[citation needed] Further, congruent
sides in the original polygon yields congruent angles in the
dual, and conversely. For example, the dual of a highly acute
isosceles triangle is an obtuse isosceles triangle.  In the
Dorman Luke construction, each face of a dual polyhedron is the
dual polygon of the corresponding vertex figure.  Duality in
quadrilaterals[edit]  As an example