Triangular-heptagonal duoprism

The triangular-heptagonal duoprism or theddip, also known as the 3-7 duoprism, is a uniform duoprism that consists of 3 heptagonal prisms and 7 triangular prisms, with 2 of each meeting at each vertex. It can also be seen as a convex segmentochoron, being a heptagon atop a heptagonal prism.

Vertex coordinates
The coordinates of a triangular-heptagonal duoprism, centered at the origin and with edge length 2sin(π/7), are given by: where j = 2, 4, 6.
 * $$\left(0,\frac{2\sqrt3}3\sin\frac{\pi}7,1,0\right),$$
 * $$\left(0,\frac{2\sqrt3}3\sin\frac{\pi}7,\cos\left(\frac{j\pi}7\right),±\sin\left(\frac{j\pi}7\right)\right),$$
 * $$\left(±\sin\frac{\pi}7,-\frac{\sqrt3}3\sin\frac{\pi}7,1,0\right),$$
 * $$\left(±\sin\frac{\pi}7,-\frac{\sqrt3}3\sin\frac{\pi}7,\cos\left(\frac{j\pi}7\right),±\sin\left(\frac{j\pi}7\right)\right),$$