Freese's Dissection of a Regular Hexagon into a Square and an Equilateral Triangle
This Demonstration shows Freese's dissection of a regular hexagon into a square and an equilateral triangle.
See "Freese's Unique Point of View" [1, pp. 46–49].
 G. N. Frederickson, Piano-Hinged Dissections: Time to Fold!, Wellesley, MA: A. K. Peters, 2006.