Freese's Dissection of a Regular Hexagon into Two Congruent Regular Hexagons
This Demonstration shows Freese's dissection of a regular hexagon into two congruent regular hexagons.
See "Giving Freese His Due" [1, pp. 124–126].
 G. N. Frederickson, Piano-Hinged Dissections: Time to Fold!, Wellesley, MA: A. K. Peters, 2006.