Twist-hinged hexagons for 1² + 2² + 2² = 3²

Frederickson's twist-hinged dissection for hexagons with 1² + 2² + 2² = 3²  (8)

Flipe-hinged pieces

Reference :

Updates to Chapter 22 of  Hinged dissections : Swinging & twisting, by Frederickson, Greg N.

http://www.cs.purdue.edu/homes/gnf/book2/Booknews2/ch22.html#THH