Octagrammic-enneagrammic duoprism

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Octagrammic-enneagrammic duoprism
Rank4
TypeUniform
Notation
Bowers style acronymStostedip
Coxeter diagramx8/3o x9/2o ()
Elements
Cells9 octagrammic prisms, 8 enneagrammic prisms
Faces72 squares, 9 octagrams, 8 enneagrams
Edges72+72
Vertices72
Vertex figureDigonal disphenoid, edge lengths 2–2 (base 1), 2cos(2π/9) (base 2), 2 (sides)
Measures (edge length 1)
Circumradius
Hypervolume
Dichoral anglesStop–8/3–stop: 100°
 Stop–4–step: 90°
 Step–9/2–step: 45°
Central density6
Number of external pieces34
Level of complexity24
Related polytopes
ArmySemi-uniform oedip
RegimentStostedip
DualOctagrammic-enneagrammic duotegum
ConjugatesOctagonal-enneagonal duoprism, Octagonal-enneagrammic duoprism, Octagonal-great enneagrammic duoprism, Octagrammic-enneagonal duoprism, Octagrammic-great enneagrammic duoprism
Abstract & topological properties
Flag count1728
Euler characteristic0
OrientableYes
Properties
SymmetryI2(8)×I2(9), order 288
ConvexNo
NatureTame

The octagrammic-enneagrammic duoprism, also known as stostedip or the 8/3-9/2 duoprism, is a uniform duoprism that consists of 9 octagrammic prisms and 8 enneagrammic prisms, with 2 of each at each vertex.

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

Vertex coordinates[edit | edit source]

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

  • ,
  • ,
  • ,
  • ,
  • ,
  • ,

where j = 2, 4, 8.

Representations[edit | edit source]

An octagrammic-enneagrammic duoprism has the following Coxeter diagrams:

External links[edit | edit source]