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, as 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:
 * (0, 2sin(π/7)$\sqrt{2}$/3, 1, 0),
 * (0, 2sin(π/7)$\sqrt{3}$/3, cos(2π/7), ±sin(2π/7)),
 * (0, 2sin(π/7)$\sqrt{3}$/3, cos(4π/7), ±sin(4π/7)),
 * (0, 2sin(π/7)$\sqrt{3}$/3, cos(6π/7), ±sin(6π/7)),
 * (±sin(π/7), –sin(π/7)$\sqrt{3}$/3, 1, 0),
 * (±sin(π/7), –sin(π/7)$\sqrt{3}$/3, cos(2π/7), ±sin(2π/7)),
 * (±sin(π/7), –sin(π/7)$\sqrt{3}$/3, cos(4π/7), ±sin(4π/7)),
 * (±sin(π/7), –sin(π/7)$\sqrt{3}$/3, cos(6π/7), ±sin(6π/7)).