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GeezerVison is showing mathworld.wolfram.com — Pentakis Dodecahedron -- from Wolfram MathWorld Pentakis Dodecahedron
The pentakis dodecahedron is the 60-faced dual polyhedron of the truncated icosahedron (Holden 1971,
p. 55). It can be constructed by augmentation
of a unit edge-length dodecahedron by a pyramid
with height
It is Wenninger dual
A tetrahedron 10-compound, cube 5-compound, icosahedron, and dodecahedron can be inscribed in the vertices of the pentakis dodecahedron (E. Weisstein, Dec. 25-27, 2009). The pentakis dodecahedron is he convex hull of the small triambic icosahedron hull. Taking the dual of a truncated icosahedron with unit edge lengths gives a pentakis dodecahedron with edge lengths
Normalizing so that
The inscribed realization illustrated above has the same combinatorial structure as the dual polyhedron
described earlier, but different proportions. The dual
polyhedron has vertices at two distances
from its center, whereas all 32 vertices
of the inscribed realization lie on one sphere.
It is obtained from the convex hull of the 12 vertices
of a regular icosahedron on the unit
sphere together with the radial projections of its 20 face centers onto the sphere. Hoehner (2026) proved that this realization uniquely
maximizes volume among convex polyhedra with at most 32 vertices
on the unit sphere, up to orthogonal
transformations. Its volume is See alsoArchimedean Dual, Archimedean Solid, Dual Polyhedron, Hexecontahedron, Pentakis Dodecahedral Graph, Truncated IcosahedronExplore with Wolfram|AlphaMore things to try: ReferencesHoehner, S. "On Maximum Volume Polytopes Inscribed in the Sphere." 7 Nov 2026. https://arxiv.org/abs/2611.10777.Holden, A. Shapes, Space, and Symmetry. New York: Columbia University Press, p. 55, 1971.Kabai, S. Mathematical Graphics I: Lessons in Computer Graphics Using Mathematica. Püspökladány, Hungary: Uniconstant, p. 153, 2002.Wenninger, M. J. Dual Models. Cambridge, England: Cambridge University Press, p. 18, 1983.Referenced on Wolfram|AlphaPentakis DodecahedronCite this as:Weisstein, Eric W. "Pentakis Dodecahedron." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/PentakisDodecahedron.html Subject classifications | ||||||||||||||||
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