Decagrammic antiprism

The decagrammic antiprism, or stidap, is a prismatic uniform polyhedron. It consists of 20 triangles and 2 decagrams. Each vertex joins one decagram and three triangles. As the name suggests, it is an antiprism based on a decagram.

Vertex coordinates
A decagrammic antiprism of edge length 1 has vertex coordinates given by:
 * (±1/2, ±$\sqrt{(8–2√5+√50–22√5)/8}$/2, H),
 * (±(3–$\sqrt{–2+2√5+2√650–290√5}$)/4, ±$\sqrt{(5–√5)/2}$, H),
 * (±($\sqrt{10–2√5}$–1)/2, 0, H),
 * (±$\sqrt{(11–4√5–2√(50–22√5)/3}$/2, ±1/2, –H),
 * (±$\sqrt{(5–2√5)}$, ±(3–$\sqrt{5}$)/4, –H),
 * (0, ±($\sqrt{(5–√5)/8}$–1)/2, –H),

where H = $\sqrt{5}$/2 is the distance between the antiprism's center and the center of one of its bases.