Dimitris Vartziotis and Joachim Wipper, On the construction
of regular polygons and generalized Napoleon vertices,
Forum Geometricorum, 9 (2009) 213--223.
Abstract: An algebraic foundation for the derivation of geometric
construction schemes transforming arbitrary polygons with n vertices into
k-regular n-gons is given. It is based on circulant polygon transformations
and the associated eigenpolygon decompositions leading to the definition
of generalized Napoleon vertices. Geometric construction schemes are
derived exemplarily for different choices of n and k.