Hinged Dissection of Equilateral Triangles
This Demonstration gives hinged dissections of various sets of equilateral triangles due to Bradley (), Collison (), and Frederickson (). The side lengths are proportional to the square roots of the areas.
G. N. Frederickson, Hinged Dissections: Swinging & Twisting, New York: Cambridge University Press, 2002 pp. 72-74.