# Heptagrammic-decagonal duoprism

Heptagrammic-decagonal duoprism
Rank4
TypeUniform
SpaceSpherical
Bowers style acronymShededip
Info
Coxeter diagramx7/2o x10o
SymmetryI2(7)×I2(10), order 280
RegimentShededip
Elements
Vertex figureDigonal disphenoid, edge lengths 2cos(2π/7) (base 1), (5+5)/2 (base 2), 2 (sides)
Cells10 heptagrammic prisms, 7 decagonal prisms
Faces70 squares, 10 heptagrams, 7 decagons
Edges70+70
Vertices70
Measures (edge length 1)
Circumradius$\sqrt{\frac{1}{4\sin^2\frac{2\pi}{7}}+\frac{3+\sqrt{5}}{2}}≈1.73983$ Hypervolume$\frac{35\sqrt{5+2\sqrt{5}}}{8\tan\frac{2\pi}{7}}≈10.73787$ Dichoral anglesShip–7/2–ship: 144°
Dip–10–dip: 3π/7 ≈ 77.14286°
Ship–4–dip: 90°
Central density2
Related polytopes
DualHeptagrammic-decagonal duotegum
ConjugatesHeptagonal-decagonal duoprism, Heptagonal-decagrammic duoprism, Heptagrammic-decagrammic duoprism, Great heptagrammic-decagonal duoprism, Great heptagrammic-decagrammic duoprism
Properties
ConvexNo
OrientableYes
NatureTame

The heptagrammic-decagonal duoprism, also known as shededip or the 7/2-10 duoprism, is a uniform duoprism that consists of 10 heptagrammic prisms and 7 decagonal prisms, with 2 of each meeting at each vertex.

The name can also refer to the great heptagrammic-decagonal duoprism.

## Vertex coordinates

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

• (1, 0, ±sin(2π/7), ±sin(2π/7)5+25),
• (1, 0, ±sin(2π/7)(3+5)/2, ±sin(2π/7)(5+5)/2),
• (1, 0, ±sin(2π/7)(1+5), 0),
• (cos(2π/7), ±sin(2π/7), ±sin(2π/7), ±sin(2π/7)5+25),
• (cos(2π/7), ±sin(2π/7), ±sin(2π/7)(3+5)/2, ±sin(2π/7)(5+5)/2),
• (cos(2π/7), ±sin(2π/7), ±sin(2π/7)(1+5), 0),
• (cos(4π/7), ±sin(4π/7), ±sin(2π/7), ±sin(2π/7)5+25),
• (cos(4π/7), ±sin(4π/7), ±sin(2π/7)(3+5)/2, ±sin(2π/7)(5+5)/2),
• (cos(4π/7), ±sin(4π/7), ±sin(2π/7)(1+5), 0),
• (cos(6π/7), ±sin(6π/7), ±sin(2π/7), ±sin(2π/7)5+25),
• (cos(6π/7), ±sin(6π/7), ±sin(2π/7)(3+5)/2, ±sin(2π/7)(5+5)/2),
• (cos(6π/7), ±sin(6π/7), ±sin(2π/7)(1+5), 0).