Small tridecagram

The small tridecagram, or sat, is a non-convex polygon with 13 sides. It's created by taking the first stellation of a tridecagon. A regular small tridecagram has equal sides and equal angles.

It is one of five regular 13-sided star polygons, the other three being the tridecagram, the medial tridecagram, the great tridecagram, and the grand tridecagram.