My paper has finally appeared on the arXiv after 18 days in moderation! I submitted it on June 23rd.
"The Moduli Space of Acute Triangles"
Abstract: 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.
https://arxiv.org/abs/2407.06201
Thanks to @highergeometer for noticing this even before I did!