Английская Википедия:Icosahedral bipyramid

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Icosahedral bipyramid
Файл:Icosahedral bipyramid-ortho.png
Orthogonal projection
Central icosahedron with 30 blue edges and 20 red vertices, apex vertices in yellow, connecting to icosahedron with 24 black edges.
Type Polyhedral bipyramid
Schläfli symbol {3,5} + { }
dt{2,5,3}
Coxeter-Dynkin Шаблон:CDD
Cells 40 {3,3} Файл:Tetrahedron.png
Faces 80 {3}
Edges 54 (30+12+12)
Vertices 14 (12+2)
Dual Dodecahedral prism
Symmetry group [2,3,5], order 240
Properties convex, regular-celled, Blind polytope

In 4-dimensional geometry, the icosahedral bipyramid is the direct sum of a icosahedron and a segment, {3,5} + { }. Each face of a central icosahedron is attached with two tetrahedra, creating 40 tetrahedral cells, 80 triangular faces, 54 edges, and 14 vertices.[1] An icosahedral bipyramid can be seen as two icosahedral pyramids augmented together at their bases.

It is the dual of a dodecahedral prism, Coxeter-Dynkin diagram Шаблон:CDD, so the bipyramid can be described as Шаблон:CDD. Both have Coxeter notation symmetry [2,3,5], order 240.

Having all regular cells (tetrahedra), it is a Blind polytope.

See also

References

Шаблон:Reflist

External links

Шаблон:Polychora-stub