Stellated tetradecagon

The stellated tetradecagon or stad is a polygon compound composed of two heptagons. As such it has 14 edges and 14 vertices.

As the name suggests, it is the first stellation of the tetradecagon.

Its quotient prismatic equivalent is the heptagonal antiprism, which is three-dimensional.

Vertex coordinates
Coordinates for a of edge length 2sin(π/7), centered at the origin, are:


 * $$\left(\pm1,\,0\right),$$
 * $$\left(\pm\cos\frac{\pi}{7},\,\pm\sin\frac{\pi}{7}\right),$$
 * $$\left(\pm\cos\frac{2\pi}{7},\,\pm\sin\frac{2\pi}{7}\right),$$
 * $$\left(\pm\cos\frac{3\pi}{7},\,\pm\sin\frac{3\pi}{7}\right).$$