Octagrammic-enneagonal duoprism

The Octagrammic-enneagonal duoprism, also known as stoendip or the 8/3-9 duoprism, is a uniform duoprism that consists of 9 octagrammic prisms and 8 enneagonal prisms, with 2 of each meeting at each vertex.

Coordinates
The vertex coordinates of a octagrammic-enneagonal duoprism, centered at the origin and with edge length 2sin(π/9), are given by:


 * (±sin(π/9)($\sqrt{2-√2}$–1), ±sin(π/9), 1, 0),
 * (±sin(π/9)($\sqrt{2}$–1), ±sin(π/9), cos(2π/9), ±sin(2π/9)),
 * (±sin(π/9)($\sqrt{(2–√2)/2+1/[4sin^{2}(π/9)]}$–1), ±sin(π/9), cos(4π/9), ±sin(4π/9)),
 * (±sin(π/9)($\sqrt{2}$–1), ±sin(π/9), –1/2, ±$\sqrt{2}$/2),
 * (±sin(π/9)($\sqrt{2}$–1), ±sin(π/9), cos(8π/9), ±sin(8π/9)),
 * (±sin(π/9), ±sin(π/9)($\sqrt{2}$–1), 1, 0),
 * (±sin(π/9), ±sin(π/9)($\sqrt{2}$–1), cos(2π/9), ±sin(2π/9)),
 * (±sin(π/9), ±sin(π/9)($\sqrt{3}$–1), cos(4π/9), ±sin(4π/9)),
 * (±sin(π/9), ±sin(π/9)($\sqrt{2}$–1), –1/2, ±$\sqrt{2}$/2),
 * (±sin(π/9), ±sin(π/9)($\sqrt{2}$–1), cos(8π/9), ±sin(8π/9)).