Generalizing the Petr-Douglas-Neumann Theorem on N-Gons
Stephen B. Gray · American Mathematical Monthly · 2003
geometry is the construction of similar figures on each side of a polygon, and the prop-erties of the new polygon so formed. This subject, still active, has been investigated for over a century. Merriell [18] surveys the field, mentioning constructions using similar triangles as far back as 1870. Probably the best known such theorem is “Napoleon’s