  As an introduction to the concept of "moduli space" we consider the moduli
space of similarity classes of acute and right triangles in the plane. This has
a map to the moduli space of elliptic curves which is onto and generically
three-to-one. The reason is that from any acute or right triangle we can
construct an elliptic curve, and every elliptic curve is isomorphic to one
constructed this way.
