Folding the regular pentagon

Abstract

I n his recent paper Two beginnings of geometry and folding: Hermann Wiener and Sundara Row, Michael Friedman (2016) has touched on a neglected aspect of the history of mathematics which is often referred to as recreational mathematics. There is a vast literature on the subject which has often contributed to the more formal side of mathematics and does not often feature in history textbooks although David Singmaster has published a bibliography of recreational mathematics which is extensive. Excerpts were included in BSHM newsletters. Because the history of recreational mathematics is neglected somewhat, it sometimes means that origins of some aspects of mathematics are lost. Such a case is the folding of polygons as knots particularly the pentagonal knot in Friedman’s Figure 2. He says