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|align=center colspan=3|'''Great triambic icosahedron'''<BR>and<BR>'''Medial triambic icosahedron'''
|align=center colspan=3|'''Great triambic icosahedron'''<BR>and<BR>'''Medial triambic icosahedron'''
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|align=center colspan=3|[[File:DU41 medial triambic icosahedron.png|280px]]
|align=center colspan=1.5|[[File:DU47 great triambic icosahedron.png|280px]]
|align=center colspan=1.5|[[File:DU41 medial triambic icosahedron.png|280px]]
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|bgcolor=#e7dcc3|Types
|bgcolor=#e7dcc3|Types
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|colspan=3 valign=top align=center|[[File:Ninth stellation of icosahedron facets.png|240px]]<BR>[[Stellation diagram]]
|colspan=3 valign=top align=center|[[File:Ninth stellation of icosahedron facets.png|240px]]<BR>[[Stellation diagram]]
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In [[geometry]], the '''great triambic icosahedron''' and '''medial triambic icosahedron''' are a visually identical [[Dual polyhedron|dual]] [[uniform polyhedra]]. The exterior surface also represents a [[Great_triambic_icosahedron#As_a_stellation|stellation]] of the [[icosahedron]].
In [[geometry]], the '''great triambic icosahedron''' and '''medial triambic icosahedron''' are a visually identical [[Dual polyhedron|dual]] [[uniform polyhedra]]. The exterior surface also represents a [[Great_triambic_icosahedron#As_a_stellation|stellation]] of the [[icosahedron]]. The only way to differentiate these two polyhedra is to mark which intersections between edges are true [[vertex|vertices]] and which are not. In the above images, true vertices are marked by gold spheres.


The 12 vertices of the [[convex hull]] matches the [[vertex arrangement]] of an [[icosahedron]].
The 12 vertices of the [[convex hull]] matches the [[vertex arrangement]] of an [[icosahedron]].

Revision as of 10:49, 5 August 2011

Great triambic icosahedron
and
Medial triambic icosahedron
Types Dual uniform polyhedra
Symmetry group Ih
Name Great triambic icosahedron Medial triambic icosahedron
Index references DU47 DU41
Elements F = 20, E = 60
V = 32 (χ = -8)
F = 20, E = 60
V = 24 (χ = -16)
Isohedral faces
Duals
Great ditrigonal icosidodecahedron

Ditrigonal dodecadodecahedron
Stellation
Icosahedron: W34

Stellation diagram

In geometry, the great triambic icosahedron and medial triambic icosahedron are a visually identical dual uniform polyhedra. The exterior surface also represents a stellation of the icosahedron. The only way to differentiate these two polyhedra is to mark which intersections between edges are true vertices and which are not. In the above images, true vertices are marked by gold spheres.

The 12 vertices of the convex hull matches the vertex arrangement of an icosahedron.

Great triambic icosahedron

The great triambic icosahedron is the dual of the great ditrigonal icosidodecahedron, U47. It has 20 inverted-hexagonal faces, shaped like a three-bladed propeller. It has 32 vertices: 12 exterior points, and 20 hidden inside. It has 60 edges.

Medial triambic icosahedron

The medial triambic icosahedron is the dual of the ditrigonal dodecadodecahedron, U41. It has 20 faces, each being simple concave isogonal hexagons. It has 24 vertices: 12 exterior points, and 12 hidden inside. It has 60 edges.

As a stellation

It is Wenninger's 34th model in his 9th stellation of the icosahedron

See also

References

  • Wenninger, Magnus (1974). Polyhedron Models. Cambridge University Press. ISBN 0-521-09859-9.
  • Wenninger, Magnus (1983). Dual Models. Cambridge University Press. ISBN 978-0-521-54325-5. MR730208.