Cubitruncated cuboctahedron

{{Short description|Polyhedron with 20 faces}}

{{Uniform polyhedra db|Uniform polyhedron stat table|ctCO}}

File:Cubitruncated cuboctahedron.stl

In geometry, the cubitruncated cuboctahedron or cuboctatruncated cuboctahedron is a nonconvex uniform polyhedron, indexed as U16. It has 20 faces (8 hexagons, 6 octagons, and 6 octagrams), 72 edges, and 48 vertices,{{Cite web|url=https://www.mathconsult.ch/static/unipoly/16.html|title=16: cubitruncated cuboctahedron|last=Maeder|first=Roman|date=|website=MathConsult|url-status=live|archive-url=https://web.archive.org/web/20150329074117/http://www.mathconsult.ch:80/static/unipoly/16.html |archive-date=2015-03-29 |access-date=}} and has a shäfli symbol of tr{4,3/2}

Convex hull

Its convex hull is a nonuniform truncated cuboctahedron.

class=wikitable width=200

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Convex hull

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Cubitruncated cuboctahedron

Orthogonal projection

Cartesian coordinates

Cartesian coordinates for the vertices of a cubitruncated cuboctahedron are all the permutations of

: (±({{radic|2}}−1), ±1, ±({{radic|2}}+1))

{{clear}}

Related polyhedra

= Tetradyakis hexahedron=

{{Uniform polyhedra db|Uniform dual polyhedron stat table|ctCO}}

File:Tetradyakis hexahedron.stl

The tetradyakis hexahedron (or great disdyakis dodecahedron) is a nonconvex isohedral polyhedron. It has 48 intersecting scalene triangle faces, 72 edges, and 20 vertices.

== Proportions ==

The triangles have one angle of \arccos(\frac{3}{4})\approx 41.409\,622\,109\,27^{\circ}, one of \arccos(\frac{1}{6}+\frac{7}{12}\sqrt{2})\approx 7.420\,694\,647\,42^{\circ} and one of \arccos(\frac{1}{6}-\frac{7}{12}\sqrt{2})\approx 131.169\,683\,243\,31^{\circ}. The dihedral angle equals \arccos(-\frac{5}{7})\approx 135.584\,691\,402\,81^{\circ}. Part of each triangle lies within the solid, hence is invisible in solid models.

It is the dual of the uniform cubitruncated cuboctahedron.

See also

References

{{Reflist}}

  • {{Citation | last1=Wenninger | first1=Magnus | author1-link=Magnus Wenninger | title=Dual Models | publisher=Cambridge University Press | isbn=978-0-521-54325-5 |mr=730208 | year=1983}} p. 92