Pseudo-deltoidal_icositetrahedron

Pseudo-deltoidal icositetrahedron

Pseudo-deltoidal icositetrahedron

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The pseudo-deltoidal icositetrahedron is a convex polyhedron with 24 congruent kites as its faces. It is the dual of the elongated square gyrobicupola, also known as the pseudorhombicuboctahedron.

Pseudo-deltoidal icositetrahedron

(see 3D model)
TypeJohnson dual,
pseudo-uniform dual
Faces24, congruent
Face polygon
Kite with:
1 obtuse angle
3 equal acute angles
Edges24 short + 24 long = 48
Vertices8 of degree 3
18 of degree 4
26 in all
Vertex configurations4.4.4 (for 8 vertices)
4.4.4.4 (for 2+8+8 vertices)
Symmetry groupD4d = D4v, [2+,24], (2*4), order 4×4
Rotation groupD4, [2,4]+, (224), order 2×4
Dihedral anglesame value for short & long edges:

Propertiesconvex, regular vertices[1]
Net
(click to enlarge)
Dual polyhedron
3D model of a pseudo-deltoidal icositetrahedron

As the pseudorhombicuboctahedron is tightly related to the rhombicuboctahedron, but has a twist along an equatorial belt of faces (and edges), the pseudo-deltoidal icositetrahedron is tightly related to the deltoidal icositetrahedron, but has a twist along an equator of (vertices and) edges.

Properties

Vertices

As the faces of the pseudorhombicuboctahedron are regular, the vertices of the pseudo-deltoidal icositetrahedron are regular.[1] But due to the twist, these 26 vertices are of four different kinds:

  • eight vertices connecting three short edges (yellow vertices in 1st figure below),
  • two apices connecting four long edges (top and bottom vertices, light red in 1st figure below),
  • eight vertices connecting four alternate edges: short-long-short-long (dark red vertices in 1st figure below),
  • eight vertices connecting one short and three long edges (twisted-equator vertices, medium red in 1st figure below).

Edges

A pseudo-deltoidal icositetrahedron has 48 edges: 24 short and 24 long, in the ratio of their lengths are and respectively, if its dual pseudo-rhombicuboctahedron has unit edge length.[2]

Faces

As the pseudorhombicuboctahedron has only one type of vertex figure, the pseudo-deltoidal icositetrahedron has only one shape of face (it is monohedral); its faces are congruent kites. But due to the twist, the pseudorhombicuboctahedron is not vertex-transitive, with its vertices in two different symmetry orbits (*), and the pseudo-deltoidal icositetrahedron is not face-transitive, with its faces in two different symmetry orbits (*) (it is 2-isohedral); these 24 faces are of two different kinds:

  • eight faces with light red, dark red, yellow, dark red vertices (top and bottom faces, light red in 1st figure below),
  • sixteen faces with yellow, dark red, medium red, medium red vertices (side faces, blue in 1st figure below).

(*) (three different symmetry orbits if we only consider rotational symmetries)

Pseudo- and actual deltoidal icositetrahedron
Pseudo- and actual rhombicuboctahedron
Pseudo- and actual deltoidal icositetrahedron
Pseudo- and actual great deltoidal icositetrahedron
Pseudo-deltoidal icositetrahedron as die

References

  1. "duality". www.polyhedra-world.nc. Retrieved 2022-10-26.



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This article uses material from the Wikipedia article Pseudo-deltoidal_icositetrahedron, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.