Great hexadecagram

The great hexadecagram, or gahd, is a non-convex polygon with 16 sides. It's created by taking the sixth stellation of a hexadecagon. A regular great hexadecagram has equal sides and equal angles.

It is one of three regular 16-sided star polygons, the other two being the small hexadecagram and the hexadecagram.

It is the uniform quasitruncation of the octagon.

Vertex coordinates
The vertices of a regular small hexadecagram of edge length 1 are given by all permutations of:


 * $$\left(±\frac12,\,±\frac{-1-\sqrt2+\sqrt{4+2\sqrt2}}{2}\right),$$
 * $$\left(±\frac{\sqrt{2+\sqrt2}-1}{2},\,±\frac{1+\sqrt2-\sqrt{2+\sqrt2}}{2}\right).$$