Great dodecahedron: Difference between revisions
AwesoMan3000 (talk | contribs) |
Rescuing 1 sources and tagging 0 as dead. #IABot (v1.6beta3) |
||
Line 64: | Line 64: | ||
* {{mathworld | urlname = DodecahedronStellations| title =Three dodecahedron stellations}} |
* {{mathworld | urlname = DodecahedronStellations| title =Three dodecahedron stellations}} |
||
* [http://gratrix.net/polyhedra/uniform/summary Uniform polyhedra and duals] |
* [http://gratrix.net/polyhedra/uniform/summary Uniform polyhedra and duals] |
||
* [http://bulatov.org/metal/dodecahedron_7.html Metal sculpture of Great Dodecahedron] |
* [http://bulatov.org/metal/dodecahedron_7.html Metal sculpture of Great Dodecahedron] |
||
{{Star polyhedron navigator}} |
{{Star polyhedron navigator}} |
Revision as of 04:16, 23 October 2017
Great dodecahedron | |
---|---|
Type | Kepler–Poinsot polyhedron |
Stellation core | regular dodecahedron |
Elements | F = 12, E = 30 V = 12 (χ = -6) |
Faces by sides | 12{5} |
Schläfli symbol | {5,5⁄2} |
Face configuration | V(5⁄2)5 |
Wythoff symbol | 5⁄2 | 2 5 |
Coxeter diagram | |
Symmetry group | Ih, H3, [5,3], (*532) |
References | U35, C44, W21 |
Properties | Regular nonconvex |
(55)/2 (Vertex figure) |
Small stellated dodecahedron (dual polyhedron) |
In geometry, the great dodecahedron is a Kepler–Poinsot polyhedron, with Schläfli symbol {5,5/2} and Coxeter–Dynkin diagram of . It is one of four nonconvex regular polyhedra. It is composed of 12 pentagonal faces (six pairs of parallel pentagons), with five pentagons meeting at each vertex, intersecting each other making a pentagrammic path.
The discovery of the great dodecahedron is sometimes credited to Louis Poinsot in 1810, though there is a drawing of something very similar to a great dodecahedron in the 1568 book Perspectiva Corporum Regularium by Wenzel Jamnitzer.
Images
Transparent model | Spherical tiling |
---|---|
(With animation) |
This polyhedron represents a spherical tiling with a density of 3. (One spherical pentagon face is shown above in yellow) |
Net | Stellation |
× 20 Net for surface geometry; twenty isosceles triangular pyramids, arranged like the faces of an icosahedron |
It can also be constructed as the second of three stellations of the dodecahedron, and referenced as Wenninger model [W21]. |
Related polyhedra
It shares the same edge arrangement as the convex regular icosahedron.
If the great dodecahedron is considered as a properly intersected surface geometry, it has the same topology as a triakis icosahedron with concave pyramids rather than convex ones. The excavated dodecahedron can be seen as the same process applied to a regular dodecahedron.
A truncation process applied to the great dodecahedron produces a series of nonconvex uniform polyhedra. Truncating edges down to points produces the dodecadodecahedron as a rectified great dodecahedron. The process completes as a birectification, reducing the original faces down to points, and producing the small stellated dodecahedron.
Name | Small stellated dodecahedron | Dodecadodecahedron | Truncated great dodecahedron |
Great dodecahedron |
---|---|---|---|---|
Coxeter-Dynkin diagram |
||||
Picture |
Usage
- This shape was the basis for the Rubik's Cube-like Alexander's Star puzzle.
- The great dodecahedron provides an easy mnemonic for the binary Golay code[1]
See also
References
- ^ * Baez, John "Golay code," Visual Insight, December 1, 2015.
External links
- Weisstein, Eric W., "Great dodecahedron" ("Uniform polyhedron") at MathWorld.
- Weisstein, Eric W. "Three dodecahedron stellations". MathWorld.
- Uniform polyhedra and duals
- Metal sculpture of Great Dodecahedron
Stellations of the dodecahedron | ||||||
Platonic solid | Kepler–Poinsot solids | |||||
Dodecahedron | Small stellated dodecahedron | Great dodecahedron | Great stellated dodecahedron | |||
---|---|---|---|---|---|---|