Square-heptagonal duoprism

The square-heptagonal duoprism or shedip, also known as the 4-7 duoprism, is a uniform duoprism that consists of 4 heptagonal prisms, 7 square prisms and 28 vertices.

Coordinates
The coordinates of a square-heptagonal duoprism, centered at the origin and with edge length 2sin(π/7), are given by:


 * (±sin(π/7), ±sin(π/7), 1, 0),
 * (±sin(π/7), ±sin(π/7), cos(2π/7), ±sin(2π/7)),
 * (±sin(π/7), ±sin(π/7), cos(4π/7), ±sin(4π/7)),
 * (±sin(π/7), ±sin(π/7), cos(6π/7), ±sin(6π/7)).