Truncated cube

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Truncated cube
Truncated cube
(Click here for rotating model)
Type Archimedean solid
Uniform polyhedron
Elements F = 14, E = 36, V = 24 (χ = 2)
Faces by sides 8{3}+6{8}
Conway notation tC
Schläfli symbols t{4,3}
t0,1{4,3}
Wythoff symbol 2 3 | 4
Coxeter diagram CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
Symmetry group Oh, BC3, [4,3], (*432), order 48
Rotation group O, [4,3]+, (432), order 24
Dihedral Angle 3-8:125°15'51"
8-8:90°
References U09, C21, W8
Properties Semiregular convex
Truncated hexahedron.png
Colored faces
Truncated cube
3.8.8
(Vertex figure)
Triakisoctahedron.jpg
Triakis octahedron
(dual polyhedron)
Truncated hexahedron flat.svg
Net

In geometry, the truncated cube, or truncated hexahedron, is an Archimedean solid. It has 14 regular faces (6 octagonal and 8 triangular), 36 edges, and 24 vertices.

If the truncated cube has unit edge length, its dual triakis octahedron has edges of lengths 2 and \scriptstyle {2+\sqrt{2}}.

Area and volume[edit]

The area A and the volume V of a truncated cube of edge length a are:

A = 2\left(6+6\sqrt{2}+\sqrt{3}\right)a^2 \approx 32.4346644a^2
V = \frac{1}{3}\left(21+14\sqrt{2}\right)a^3 \approx 13.5996633a^3.

Orthogonal projections[edit]

The truncated cube has five special orthogonal projections, centered, on a vertex, on two types of edges, and two types of faces: triangles, and octagons. The last two correspond to the B2 and A2 Coxeter planes.

Orthogonal projections
Centered by Vertex Edge
3-8
Edge
8-8
Face
Octagon
Face
Triangle
Truncated
cube
Cube t01 v.png Cube t01 e38.png Cube t01 e88.png 3-cube t01 B2.svg 3-cube t01.svg
Triakis
octahedron
Dual truncated cube t01 v.png Dual truncated cube t01 e8.png Dual truncated cube t01 e88.png Dual truncated cube t01 B2.png Dual truncated cube t01.png
Projective
symmetry
[2] [2] [2] [4] [6]

Spherical tiling[edit]

The truncated cube can also be represented as a spherical tiling, and projected onto the plane via a stereographic projection. This projection is conformal, preserving angles but not areas or lengths. Straight lines on the sphere are projected as circular arcs on the plane.

Uniform tiling 432-t01.png Truncated cube stereographic projection octagon.png
octagon-centered
Truncated cube stereographic projection triangle.png
triangle-centered
Orthographic projection Stereographic projections

Cartesian coordinates[edit]

The following Cartesian coordinates define the vertices of a truncated hexahedron centered at the origin with edge length 2ξ:

(±ξ, ±1, ±1),
(±1, ±ξ, ±1),
(±1, ±1, ±ξ)

where ξ = \scriptstyle {\sqrt2 - 1}

The parameter ξ can be varied betweeen ±1. A value of 1 produces a cube, 0 produces a cuboctahedron, and negative values produces self-intersecting octagrammic faces.

Truncated cube sequence.png

If the self-intersected portions of the octagrams are removed, leaving squares, and truncating the triangles into hexagons, truncated octahedrons are produced, and the sequence ends with the central squares being reduced to a point, and creating an octahedron.

Dissection[edit]

Dissected truncated cube, with elements expanded apart

The truncated cube can be dissected into a central cube, with six square cupola around each of the cube's faces, and 8 regular tetrahedral in the corners. This dissection can also be seen within the runcic cubic honeycomb, with cube, tetrahedron, and rhombicuboctahedron cells.

This dissection can be used to create a Stewart toroid with all regular faces by removing two square cupola and the central cube. This excavated cube has 16 triangles, 12 squares, and 4 octagons.[1][2]

Excavated truncated cube.png

Vertex arrangement[edit]

It shares the vertex arrangement with three nonconvex uniform polyhedra:

Truncated hexahedron.png
Truncated cube
Uniform great rhombicuboctahedron.png
Nonconvex great rhombicuboctahedron
Great cubicuboctahedron.png
Great cubicuboctahedron
Great rhombihexahedron.png
Great rhombihexahedron

Related polyhedra[edit]

The truncated cube is one of a family of uniform polyhedra related to the cube and regular octahedron.

Uniform octahedral polyhedra
Symmetry: [4,3], (*432) [4,3]+
(432)
[1+,4,3] = [3,3]
(*332)
[3+,4]
(3*2)
{4,3} t{4,3} r{4,3}
r{31,1}
t{3,4}
t{31,1}
{3,4}
{31,1}
rr{4,3}
s2{3,4}
tr{4,3} sr{4,3} h{4,3}
{3,3}
h2{4,3}
t{3,3}
s{3,4}
s{31,1}
CDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node 1.png CDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node 1.png CDel node h.pngCDel 4.pngCDel node h.pngCDel 3.pngCDel node h.png CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node.png
CDel node h0.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
= CDel nodes 11.pngCDel split2.pngCDel node.png
CDel node h0.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node 1.png
= CDel nodes 11.pngCDel split2.pngCDel node 1.png
CDel node h0.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png
= CDel nodes.pngCDel split2.pngCDel node 1.png
CDel node 1.pngCDel 4.pngCDel node h.pngCDel 3.pngCDel node h.png CDel node h1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png =
CDel nodes 10ru.pngCDel split2.pngCDel node.png or CDel nodes 01rd.pngCDel split2.pngCDel node.png
CDel node h1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png =
CDel nodes 10ru.pngCDel split2.pngCDel node 1.png or CDel nodes 01rd.pngCDel split2.pngCDel node 1.png
CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node h0.png =
CDel node h.pngCDel split1.pngCDel nodes hh.png
Uniform polyhedron-43-t0.svg Uniform polyhedron-43-t01.svg Uniform polyhedron-43-t1.svg
Uniform polyhedron-33-t02.png
Uniform polyhedron-43-t12.svg
Uniform polyhedron-33-t012.png
Uniform polyhedron-43-t2.svg
Uniform polyhedron-33-t1.png
Uniform polyhedron-43-t02.png
Rhombicuboctahedron uniform edge coloring.png
Uniform polyhedron-43-t012.png Uniform polyhedron-43-s012.png Uniform polyhedron-33-t0.pngUniform polyhedron-33-t2.png Uniform polyhedron-33-t01.pngUniform polyhedron-33-t12.png Uniform polyhedron-43-h01.svg
Uniform polyhedron-33-s012.png
Duals to uniform polyhedra
V43 V3.82 V(3.4)2 V4.62 V34 V3.43 V4.6.8 V34.4 V33 V3.62 V35
CDel node f1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node f1.png CDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node f1.png CDel node f1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node f1.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node f1.png CDel node fh.pngCDel 4.pngCDel node fh.pngCDel 3.pngCDel node fh.png CDel node fh.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node fh.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node f1.png CDel node fh.pngCDel 3.pngCDel node fh.pngCDel 4.pngCDel node.png
CDel node f1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node f1.png CDel node f1.pngCDel 3.pngCDel node f1.pngCDel 3.pngCDel node f1.png CDel node.pngCDel 3.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node fh.pngCDel 3.pngCDel node fh.png CDel node f1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png CDel node.pngCDel 3.pngCDel node f1.pngCDel 3.pngCDel node f1.png CDel node fh.pngCDel 3.pngCDel node fh.pngCDel 3.pngCDel node fh.png
Octahedron.svg Triakisoctahedron.jpg Rhombicdodecahedron.jpg Tetrakishexahedron.jpg Hexahedron.svg Deltoidalicositetrahedron.jpg Disdyakisdodecahedron.jpg Pentagonalicositetrahedronccw.jpg Tetrahedron.svg Triakistetrahedron.jpg POV-Ray-Dodecahedron.svg

This polyhedron is topologically related as a part of sequence of uniform truncated polyhedra with vertex configurations (3.2n.2n), and [n,3] Coxeter group symmetry.

Dimensional family of truncated polyhedra and tilings: 3.2n.2n
Symmetry
*n32
[n,3]
Spherical Euclidean Compact hyperbolic Paracompact
*232
[2,3]
D3h
*332
[3,3]
Td
*432
[4,3]
Oh
*532
[5,3]
Ih
*632
[6,3]
P6m
*732
[7,3]
 
*832
[8,3]...
 
*∞32
[∞,3]
 
Truncated
figures
Spherical triangular prism.png
3.4.4
Uniform tiling 332-t01-1-.png
3.6.6
Uniform tiling 432-t01.png
3.8.8
Uniform tiling 532-t01.png
3.10.10
Uniform tiling 63-t01.png
3.12.12
Uniform tiling 73-t01.png
3.14.14
Uniform tiling 83-t01.png
3.16.16
H2 tiling 23i-3.png
3.∞.∞
Coxeter
Schläfli
CDel node 1.pngCDel 2.pngCDel node 1.pngCDel 3.pngCDel node.png
t{2,3}
CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 3.pngCDel node.png
t{3,3}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
t{4,3}
CDel node 1.pngCDel 5.pngCDel node 1.pngCDel 3.pngCDel node.png
t{5,3}
CDel node 1.pngCDel 6.pngCDel node 1.pngCDel 3.pngCDel node.png
t{6,3}
CDel node 1.pngCDel 7.pngCDel node 1.pngCDel 3.pngCDel node.png
t{7,3}
CDel node 1.pngCDel 8.pngCDel node 1.pngCDel 3.pngCDel node.png
t{8,3}
CDel node 1.pngCDel infin.pngCDel node 1.pngCDel 3.pngCDel node.png
t{∞,3}
Uniform dual figures
Triakis
figures
Triangular dipyramid.png
V3.4.4
Triakistetrahedron.jpg
V3.6.6
Triakisoctahedron.jpg
V3.8.8
Triakisicosahedron.jpg
V3.10.10
Tiling Dual Semiregular V3-12-12 Triakis Triangular.svg
V3.12.12
Ord7 triakis triang til.png
V3.14.14
Ord8 triakis triang til.png
V3.16.16
Ord-infin triakis triang til.png
V3.∞.∞
Coxeter CDel node f1.pngCDel 2.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 3.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 5.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 6.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 7.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 8.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel infin.pngCDel node f1.pngCDel 3.pngCDel node.png

It is topologically related to a series of polyhedra and tilings with face configuration Vn.8.8.

Dimensional family of truncated polyhedra and tilings: n.8.8
Symmetry
*n42
[n,4]
Spherical Euclidean Compact hyperbolic Paracompact
*242
[2,4]
D4h
*342
[3,4]
Oh
*442
[4,4]
P4m
*542
[5,4]
*642
[6,4]
*742
[7,4]
*842
[8,4]...
*∞42
[∞,4]
Truncated
figures
2.8.8 Uniform tiling 432-t01.png
3.8.8
Uniform tiling 44-t12.png
4.8.8
Uniform tiling 54-t12.png
5.8.8
Uniform tiling 64-t12.png
6.8.8
Uniform tiling 74-t12.png
7.8.8
Uniform tiling 84-t12.png
8.8.8
H2 tiling 24i-6.png
∞.8.8
Coxeter
Schläfli
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 2.pngCDel node.png
t{4,2}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
t{4,3}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 4.pngCDel node.png
t{4,4}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 5.pngCDel node.png
t{4,5}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 6.pngCDel node.png
t{4,6}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 7.pngCDel node.png
t{4,7}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 8.pngCDel node.png
t{4,8}
CDel node 1.pngCDel 4.pngCDel node 1.pngCDel infin.pngCDel node.png
t{4,∞}
Uniform dual figures
n-kis
figures
Spherical octagonal hosohedron.png
V2.8.8
Triakisoctahedron.jpg
V3.8.8
Tiling Dual Semiregular V4-8-8 Tetrakis Square.svg
V4.8.8
Order-4 pentakis pentagonal tiling.png
V5.8.8
Order4 hexakis hexagonal til.png
V6.8.8
Order4 heptakis heptagonal til.png
V7.8.8
Uniform tiling 83-t2.png
V8.8.8
Ord4 apeirokis apeirogonal til.png
V∞.8.8
Coxeter CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 2.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 3.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 4.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 5.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 6.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 7.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel 8.pngCDel node.png CDel node f1.pngCDel 4.pngCDel node f1.pngCDel infin.pngCDel node.png

Alternated truncation[edit]

A cube can be alternately truncated producing tetrahedral symmetry, with six hexagonal faces, and four triangles at the truncated vertices. It is one of a sequence of alternate truncations of polyhedra and tiling.

Alternate truncated cube.png

Related polytopes[edit]

The truncated cube, is second in a sequence of truncated hypercubes:

Truncated hypercubes
Regular polygon 8 annotated.svg 3-cube t01.svgTruncated hexahedron.png 4-cube t01.svgSchlegel half-solid truncated tesseract.png 5-cube t01.svg5-cube t01 A3.svg 6-cube t01.svg6-cube t01 A5.svg 7-cube t01.svg7-cube t01 A5.svg 8-cube t01.svg8-cube t01 A7.svg ...
Octagon Truncated cube Truncated tesseract Truncated 5-cube Truncated 6-cube Truncated 7-cube Truncated 8-cube
CDel node 1.pngCDel 4.pngCDel node 1.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.pngCDel 3.pngCDel node.png

See also[edit]

References[edit]

  1. ^ B. M. Stewart, Adventures Among the Toroids (1970) ISBN 978-0-686-11936-4
  2. ^ http://www.doskey.com/polyhedra/Stewart05.html
  • Williams, Robert (1979). The Geometrical Foundation of Natural Structure: A Source Book of Design. Dover Publications, Inc. ISBN 0-486-23729-X.  (Section 3-9)
  • Cromwell, P. Polyhedra, CUP hbk (1997), pbk. (1999). Ch.2 p.79-86 Archimedean solids

External links[edit]