Pentagrammic-enneagrammic duoprism

The pentagrammic-enneagrammic duoprism, also known as stastedip or the 5/2-9/2 duoprism, is a uniform duoprism that consists of 9 pentagrammic prisms and 5 enneagrammic prisms, with 2 of each meeting at each vertex.

The name can also refer to the pentagrammic-great enneagrammic duoprism.

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


 * (±sin(2π/9), –sin(2π/9)$\sqrt{5}$, 1, 0),
 * (±sin(2π/9), –sin(2π/9)$\sqrt{2}$, cos(2π/9), ±sin(2π/9)),
 * (±sin(2π/9), –sin(2π/9)$\sqrt{(5–√5)/10+1/[4sin^{2}(2π/9)]}$, cos(4π/9), ±sin(4π/9)),
 * (±sin(2π/9), –sin(2π/9)$\sqrt{5(5–2√5)}$, –1/2, ±$\sqrt{(5–2√5)/5}$/2),
 * (±sin(2π/9), –sin(2π/9)$\sqrt{(5–2√5)/5}$, cos(8π/9), ±sin(8π/9)),
 * (±sin(2π/9)($\sqrt{(5–2√5)/5}$–1)/2, sin(2π/9)$\sqrt{(5–2√5)/5}$, 1, 0),
 * (±sin(2π/9)($\sqrt{3}$–1)/2, sin(2π/9)$\sqrt{(5–2√5)/5}$, cos(2π/9), ±sin(2π/9)),
 * (±sin(2π/9)($\sqrt{5}$–1)/2, sin(2π/9)$\sqrt{(5+√5)/10}$, cos(4π/9), ±sin(4π/9)),
 * (±sin(2π/9)($\sqrt{5}$–1)/2, sin(2π/9)$\sqrt{(5+√5)/10}$, –1/2, ±$\sqrt{5}$/2),
 * (±sin(2π/9)($\sqrt{(5+√5)/10}$–1)/2, sin(2π/9)$\sqrt{5}$, cos(8π/9), ±sin(8π/9)),
 * (0, –2sin(2π/9)$\sqrt{(5+√5)/10}$, 1, 0),
 * (0, –2sin(2π/9)$\sqrt{3}$, cos(2π/9), ±sin(2π/9)),
 * (0, –2sin(2π/9)$\sqrt{5}$, cos(4π/9), ±sin(4π/9)),
 * (0, –2sin(2π/9)$\sqrt{(5+√5)/10}$, –1/2, ±$\sqrt{(5–√5)/10}$/2),
 * (0, –2sin(2π/9)$\sqrt{(5–√5)/10}$, cos(8π/9), ±sin(8π/9)).