An isopenta triangle is one of the two isosceles triangles: a triangle with two angles or a triangle with two angles . Either can be dissected into similar isopenta triangles all of equal legs.[more]
This Demonstration shows isopenta triangles and their expansions or dissections.[less]
 G. N. Frederickson, Dissections: Plane & Fancy, New York: Cambridge University Press, 1997 p. 212.