Great rhombihexahedron

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Great rhombihexahedron
Great rhombihexahedron.png
Type Uniform star polyhedron
Elements F = 18, E = 48
V = 24 (χ = −6)
Faces by sides 12{4}+6{8/3}
Wythoff symbol 2 4/3 (3/2 4/2) |
Symmetry group Oh, [4,3], *432
Index references U21, C82, W103
Dual polyhedron Great rhombihexacron
Vertex figure Great rhombihexahedron vertfig.png
4.8/3.4/3.8/5
Bowers acronym Groh

In geometry, the great rhombihexahedron is a nonconvex uniform polyhedron, indexed as U21. Its dual is the great rhombihexacron.[1] Its vertex figure is a crossed quadrilateral.

Orthogonal projections[edit]

Great rhombihexahedron ortho wireframes.png

Filling[edit]

There is some controversy on how to colour the faces of this polyhedron. Although the common way to fill in a polygon is to just colour its whole interior, this can result in some filled regions hanging as membranes over empty space. Hence, the "neo filling" is sometimes used instead as a more accurate filling. In the neo filling, orientable polyhedra are filled traditionally, but non-orientable polyhedra have their faces filled with the modulo-2 method (only odd-density regions are filled in).[2]

Great rhombihexahedron.png
Traditional filling
Great rhombihexahedron 2.png
"Neo filling"

Related polyhedra[edit]

It shares the vertex arrangement with the convex truncated cube. It additionally shares its edge arrangement with the nonconvex great rhombicuboctahedron (having 12 square faces in common), and with the great cubicuboctahedron (having the octagrammic faces in common).

Truncated hexahedron.png
Truncated cube
Uniform great rhombicuboctahedron.png
Nonconvex great rhombicuboctahedron
Great cubicuboctahedron.png
Great cubicuboctahedron
Great rhombihexahedron.png
Great rhombihexahedron

It may be constructed as the exclusive or (blend) of three octagrammic prisms.

Great rhombihexacron[edit]

Great rhombihexacron
DU21 great rhombihexacron.png
Type Star polyhedron
Face DU21 facets.png
Elements F = 24, E = 48
V = 18 (χ = −6)
Symmetry group Oh, [4,3], *432
Index references DU21
dual polyhedron Great rhombihexahedron

The great rhombihexacron is a nonconvex isohedral polyhedron. It is the dual of the uniform great rhombihexahedron (U21).[3] It has 24 identical bow-tie-shaped faces, 18 vertices, and 48 edges.[4]

It has 12 outer vertices which have the same vertex arrangement as the cuboctahedron, and 6 inner vertices with the vertex arrangement of an octahedron.

As a surface geometry, it can be seen as visually similar to a Catalan solid, the disdyakis dodecahedron, with much taller rhombus-based pyramids joined to each face of a rhombic dodecahedron.

See also[edit]

References[edit]

External links[edit]