# Octagrammic-decagrammic duoprism

The octagrammic-decagrammic duoprism, also known as stostidedip or the 8/3-10/3 duoprism, is a uniform duoprism that consists of 10 octagrammic prisms and 8 decagrammic prisms, with 2 of each meeting at each vertex.

Octagrammic-decagrammic duoprism
Rank4
TypeUniform
SpaceSpherical
Bowers style acronymStostidedip
Info
Coxeter diagramx8/3o x10/3o
SymmetryI2(8)×I2(10), order 320
ArmySemi-uniform odedip
RegimentStostidedip
Elements
Vertex figureDigonal disphenoid, edge lengths 2–2 (base 1), (5–5)/2 (base 2), 2 (sides)
Cells10 octagrammic prisms, 8 decagrammic prisms
Faces80 squares, 10 octagrams, 8 decagrams
Edges80+80
Vertices80
Measures (edge length 1)
Hypervolume55–25(2–1) ≈ 1.50472
Dichoral anglesStop–8/3–stop: 72°
Stiddip–10/3–stiddip: 45°
Stop–4–stiddip: 90°
Central density9
Related polytopes
DualOctagrammic-decagrammic duotegum
ConjugatesOctagonal-decagonal duoprism, Octagonal-decagrammic duoprism, Octagrammic-decagonal duoprism
Properties
ConvexNo
OrientableYes
NatureTame

## Vertex coordinates

The vertex coordinates of an octagrammic-decagrammic duoprism, centered at the origin and with unit edge length, are given by:

• (±(2–1)/2, ±1/2, ±1/2, ±5–2√5/2),
• (±(2–1)/2, ±1/2, ±(3–5)/4, ±(5–√5)/8),
• (±(2–1)/2, ±1/2, ±(5–1)/2, 0),
• (±1/2, ±(2–1)/2, ±1/2, ±5–2√5/2),
• (±1/2, ±(2–1)/2, ±(3–5)/4, ±(5–√5)/8),
• (±1/2, ±(2–1)/2, ±(5–1)/2, 0).