Enneagonal-enneagrammic duoprism
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Enneagonal-enneagrammic duoprism | |
---|---|
Rank | 4 |
Type | Uniform |
Notation | |
Bowers style acronym | Estedip |
Coxeter diagram | x9o x9/2o () |
Elements | |
Cells | 9 enneagonal prisms, 9 enneagrammic prisms |
Faces | 81 squares, 9 enneagons, 9 enneagrams |
Edges | 81+81 |
Vertices | 81 |
Vertex figure | Digonal disphenoid, edge lengths 2cos(π/9) (base 1), 2cos(2π/9) (base 2), √2 (sides) |
Measures (edge length 1) | |
Circumradius | |
Hypervolume | |
Dichoral angles | Step–9/2–step: 140° |
Ep–9–ep: 100° | |
Ep–4–step: 90° | |
Central density | 2 |
Number of external pieces | 27 |
Level of complexity | 12 |
Related polytopes | |
Army | Semi-uniform edip |
Regiment | Estedip |
Dual | Enneagonal-ennneagrammic duotegum |
Conjugates | Enneagonal-great enneagrammic duoprism, Enneagrammic-great enneagrammic duoprism |
Abstract & topological properties | |
Euler characteristic | 0 |
Orientable | Yes |
Properties | |
Symmetry | I2(9)×I2(9), order 324 |
Convex | No |
Nature | Tame |
The enneagonal-enneagrammic duoprism, also known as estedip or the 9-9/2 duoprism, is a uniform duoprism that consists of 9 enneagonal prisms and 9 enneagrammic prisms, with 2 of each at each vertex.
The name can also refer to the enneagonal-great enneagrammic duoprism.
Vertex coordinates[edit | edit source]
The coordinates of a enneagonal-enneagrammic duoprism, centered at the origin and with edge length 2sin(2π/9), are given by:
where j, k = 2, 4, 8.
External links[edit | edit source]
- Bowers, Jonathan. "Category A: Duoprisms".
- Klitzing, Richard. "nd-mb-dip".