An Isosceles Triangle with Vertex angles 36°. Such Triangles
occur in the Pentagram and Decagon. The legs are in a Golden Ratio to the base. For such a
Triangle,
(1) |
(2) |
(3) |
(4) |
See also Decagon, Golden Ratio, Isosceles Triangle, Pentagram
References
Pappas, T. ``The Pentagon, the Pentagram & the Golden Triangle.'' The Joy of Mathematics.
San Carlos, CA: Wide World Publ./Tetra, pp. 188-189, 1989.