Compound of ten tetrahedra

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Compound of ten tetrahedra
Type
regular compound
Coxeter symbol 2{5,3}[10{3,3}]2{3,5}[1]
Index UC6, W25
Elements
(As a compound)
10 tetrahedra:
F = 40, E = 60, V = 20
Dual compound Self-dual
Symmetry group icosahedral (Ih)
Subgroup restricting to one constituent chiral tetrahedral (T)
3D model of a compound of ten tetrahedra

The

compound. This compound was first described by Edmund Hess
in 1876.

It can be seen as a faceting of a regular dodecahedron.

As a compound

spherical tiling

It can also be seen as the

full icosahedral symmetry (Ih). It is one of five regular compounds constructed from identical Platonic solids
.

It shares the same vertex arrangement as a dodecahedron.

The compound of five tetrahedra represents two chiral halves of this compound (it can therefore be seen as a "compound of two compounds of five tetrahedra").

It can be made from the

stella octangula
on the cube's vertices (which results in a "compound of five compounds of two tetrahedra").

As a stellation

This polyhedron is a stellation of the icosahedron, and given as Wenninger model index 25.

Stellation diagram Stellation core Convex hull
Icosahedron

Dodecahedron

As a facetting

Ten tetrahedra in a dodecahedron.

It is also a

facetting of the dodecahedron, as shown at left. Concave pentagrams
can be seen on the compound where the pentagonal faces of the dodecahedron are positioned.

As a simple polyhedron

If it is treated as a simple non-convex polyhedron without self-intersecting surfaces, it has 180 faces (120 triangles and 60 concave quadrilaterals), 122 vertices (60 with degree 3, 30 with degree 4, 12 with degree 5, and 20 with degree 12), and 300 edges, giving an Euler characteristic of 122-300+180 = +2.

See also

References

  1. ^ Regular polytopes, p.98
  • .
  • . (1st Edn University of Toronto (1938))
  • , 3.6 The five regular compounds, pp.47-50, 6.2 Stellating the Platonic solids, pp.96-104

External links

Notable stellations of the icosahedron
Regular Uniform duals
Regular compounds
Regular star Others
(Convex) icosahedron Small triambic icosahedron
Medial triambic icosahedron
Great triambic icosahedron Compound of five octahedra Compound of five tetrahedra Compound of ten tetrahedra Great icosahedron Excavated dodecahedron Final stellation
The stellation process on the icosahedron creates a number of related
compounds with icosahedral symmetry
.