Truncated 8-cubes

8-cube	Truncated 8-cube	Bitruncated 8-cube	120px Tritruncated 8-cube	120px Quadritruncated 8-cube
8-orthoplex	120px Truncated 8-orthoplex	120px Bitruncated 8-orthoplex	120px Tritruncated 8-orthoplex
Orthogonal projections in BC8 Coxeter plane

In eight-dimensional geometry, a truncated 8-cube is a convex uniform 8-polytope, being a truncation of the regular 8-cube.

There are unique 7 degrees of truncation for the 8-cube. Vertices of the truncation 8-cube are located as pairs on the edge of the 8-cube. Vertices of the bitruncated 8-cube are located on the square faces of the 8-cube. Vertices of the tritruncated 7-cube are located inside the cubic cells of the 8-cube. The final truncations are best expressed relative to the 8-orthoplex.

Truncated 8-cube

Truncated 8-cube
Type	uniform 8-polytope
Schläfli symbol	t{4,3,3,3,3,3,3}
Coxeter-Dynkin diagrams
6-faces
5-faces
4-faces
Cells
Faces
Edges
Vertices
Vertex figure	Elongated 6-simplex pyramid
Coxeter groups	BC8, [3,3,3,3,3,3,4]
Properties	convex

Alternate names

• Truncated octeract (acronym tocto) (Jonathan Bowers)

Cartesian coordinates for the vertices of a truncated 8-cube, centered at the origin, are all 224 vertices are sign (4) and coordinate (56) permutations of

(±2,±2,±2,±2,±2,±2,±1,0)

Images

orthographic projections

B8			B7
			200px
[16]			[14]
B6			B5
200px			200px
[12]			[10]
B4		B3		B2
200px		200px		200px
[8]		[6]		[4]
A7		A5		A3
		200px		200px
[8]		[6]		[4]

Related polytopes

The truncated 8-cube, is seventh in a sequence of truncated hypercubes:

Truncated hypercubes

							...
Octagon	Truncated cube	Truncated tesseract	Truncated 5-cube	Truncated 6-cube	Truncated 7-cube	Truncated 8-cube

Bitruncated 8-cube

Bitruncated 8-cube
Type	uniform 8-polytope
Schläfli symbol	2t{4,3,3,3,3,3,3}
Coxeter-Dynkin diagrams
6-faces
5-faces
4-faces
Cells
Faces
Edges
Vertices
Vertex figure
Coxeter groups	BC8, [3,3,3,3,3,3,4]
Properties	convex

Alternate names

• Bitruncated octeract (acronym bato) (Jonathan Bowers)

Coordinates

Cartesian coordinates for the vertices of a truncated 8-cube, centered at the origin, are all the sign coordinate permutations of

(±2,±2,±2,±2,±2,±1,0,0)

Images

orthographic projections

B8			B7
			200px
[16]			[14]
B6			B5
200px			200px
[12]			[10]
B4		B3		B2
200px		200px		200px
[8]		[6]		[4]
A7		A5		A3
		200px		200px
[8]		[6]		[4]

Related polytopes

The bitruncated 8-cube is sixth in a sequence of bitruncated hypercubes:

Bitruncated hypercubes

						...
Bitruncated cube	Bitruncated tesseract	Bitruncated 5-cube	Bitruncated 6-cube	Bitruncated 7-cube	Bitruncated 8-cube

Tritruncated 8-cube

Tritruncated 8-cube
Type	uniform 8-polytope
Schläfli symbol	3t{4,3,3,3,3,3,3}
Coxeter-Dynkin diagrams
6-faces
5-faces
4-faces
Cells
Faces
Edges
Vertices
Vertex figure
Coxeter groups	BC8, [3,3,3,3,3,3,4]
Properties	convex

Alternate names

• Tritruncated octeract (acronym tato) (Jonathan Bowers)

Coordinates

Cartesian coordinates for the vertices of a truncated 8-cube, centered at the origin, are all the sign coordinate permutations of

(±2,±2,±2,±2,±1,0,0,0)

Images

orthographic projections

B8			B7
200px			200px
[16]			[14]
B6			B5
200px			200px
[12]			[10]
B4		B3		B2
200px		200px		200px
[8]		[6]		[4]
A7		A5		A3
200px		200px		200px
[8]		[6]		[4]

Quadritruncated 8-cube

Quadritruncated 8-cube
Type	uniform 8-polytope
Schläfli symbol	4t{3,3,3,3,3,3,4}
Coxeter-Dynkin diagrams
6-faces
5-faces
4-faces
Cells
Faces
Edges
Vertices
Vertex figure
Coxeter groups	BC8, [3,3,3,3,3,3,4] D8, [35,1,1]
Properties	convex

Alternate names

• Quadritruncated octeract (acronym oke) (Jonathan Bowers)

Coordinates

Cartesian coordinates for the vertices of a bitruncated 8-orthoplex, centered at the origin, are all sign and coordinate permutations of

(±2,±2,±2,±2,±1,0,0,0)

Images

orthographic projections

B8			B7
200px			200px
[16]			[14]
B6			B5
200px			200px
[12]			[10]
B4		B3		B2
200px		200px		200px
[8]		[6]		[4]
A7		A5		A3
200px		200px		200px
[8]		[6]		[4]

Related polytopes

2-isotopic hypercubes

Dim.	2	3	4	5	6	7	8
Name	t{4}	r{4,3}	2t{4,3,3}	2r{4,3,3,3}	3t{4,3,3,3,3}	3r{4,3,3,3,3,3}	4t{4,3,3,3,3,3,3}
Coxeter diagram
Images	60px			60px	60px	60px60px	60px60px	...
Facets		{3} {4}	t{3,3} t{3,4}	r{3,3,3} r{3,3,4}	2t{3,3,3,3} 2t{3,3,3,4}	2r{3,3,3,3,3} 2r{3,3,3,3,4}	3t{3,3,3,3,3,3} 30px 3t{3,3,3,3,3,4}
Vertex figure		Rectangle	60px Disphenoid	{3}×{4} duoprism		{3,3}×{3,4} duoprism

References

• H.S.M. Coxeter:
  • H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973
  • Kaleidoscopes: Selected Writings of H.S.M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995, ISBN 978-0-471-01003-6 [1]
    • (Paper 22) H.S.M. Coxeter, Regular and Semi Regular Polytopes I, [Math. Zeit. 46 (1940) 380-407, MR 2,10]
    • (Paper 23) H.S.M. Coxeter, Regular and Semi-Regular Polytopes II, [Math. Zeit. 188 (1985) 559-591]
    • (Paper 24) H.S.M. Coxeter, Regular and Semi-Regular Polytopes III, [Math. Zeit. 200 (1988) 3-45]
• Norman Johnson Uniform Polytopes, Manuscript (1991)
  • N.W. Johnson: The Theory of Uniform Polytopes and Honeycombs, Ph.D.
• Richard Klitzing, 8D, uniform polytopes (polyzetta) o3o3o3o3o3o3x4x - tocto, o3o3o3o3o3x3x4o - bato, o3o3o3o3x3x3o4o - tato, o3o3o3x3x3o3o4o - oke

External links

• Olshevsky, George, Cross polytope at Glossary for Hyperspace.
• Polytopes of Various Dimensions
• Multi-dimensional Glossary