- Truncated great icosahedron
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Truncated great icosahedron Type Uniform star polyhedron Elements F = 32, E = 90
V = 60 (χ = 2)Faces by sides 12{5/2}+20{6} Wythoff symbol 2 5/2 | 3 Symmetry group Ih, [5,3], *532 Index references U55, C71, W95
6.6.5/2
(Vertex figure)
Great stellapentakis dodecahedron
(dual polyhedron)In geometry, the truncated great icosahedron is a nonconvex uniform polyhedron, indexed as U55. It is given a Schläfli symbol t0,1{3,5/2} as a truncated great icosahedron.
Contents
Cartesian coordinates
Cartesian coordinates for the vertices of a truncated great icosahedron centered at the origin are all the even permutations of
- (±1, 0, ±3/τ)
- (±2, ±1/τ, ±1/τ3)
- (±(1+1/τ2), ±1, ±2/τ)
where τ = (1+√5)/2 is the golden ratio (sometimes written φ). Using 1/τ2 = 1 − 1/τ one verifies that all vertices are on a sphere, centered at the origin, with the radius squared equal to 10−9/τ. The edges have length 2.
Related polyhedra
This polyhedron is the truncation of the great icosahedron:
The truncated great stellated dodecahedron is a degenerate polyhedron, with 20 triangular faces from the truncated vertices, and 12 (hidden) pentagonal faces as truncations of the original pentagram faces, the latter forming a great dodecahedron inscribed within and sharing the edges of the icosahedron.
Name Great
stellated
dodecahedronTruncated great stellated dodecahedron Great
icosidodecahedronTruncated
great
icosahedronGreat
icosahedronCoxeter-Dynkin
diagramPicture See also
External links
Star-polyhedra navigator Kepler-Poinsot polyhedra
(Nonconvex regular polyhedra)Uniform truncations of Kepler-Poinsot polyhedra Nonconvex uniform Hemipolyhedra Duals of nonconvex uniform polyhedra medial rhombic triacontahedron · small stellapentakis dodecahedron · medial deltoidal hexecontahedron · small rhombidodecacron · medial pentagonal hexecontahedron · medial disdyakis triacontahedron · great rhombic triacontahedron · great stellapentakis dodecahedron · great deltoidal hexecontahedron · great disdyakis triacontahedron · great pentagonal hexecontahedronDuals of Nonconvex uniform
(Infinite stellations)tetrahemihexacron · hexahemioctacron · octahemioctacron · small dodecahemidodecacron · small icosihemidodecacron · great dodecahemidodecacron · great icosihemidodecacron · great dodecahemicosacron · small dodecahemicosacronThis polyhedron-related article is a stub. You can help Wikipedia by expanding it.