Truncated order-7 triangular tiling

Truncated order-7 triangular tiling
Poincaré disk model of the hyperbolic plane
Type	Hyperbolic uniform tiling
Vertex configuration	7.6.6
Schläfli symbol	t{3,7}
Wythoff symbol	2 7 \| 3
Coxeter diagram
Symmetry group	[7,3], (*732)
Dual	Heptakis heptagonal tiling
Properties	Vertex-transitive

In geometry, the order-7 truncated triangular tiling, sometimes called the hyperbolic soccerball,^[1] is a semiregular tiling of the hyperbolic plane. There are two hexagons and one heptagon on each vertex, forming a pattern similar to a conventional soccer ball (truncated icosahedron) with heptagons in place of pentagons. It has Schläfli symbol of t{3,7}.

Hyperbolic soccerball (football)

This tiling is called a hyperbolic soccerball (football) for its similarity to the truncated icosahedron pattern used on soccer balls. Small portions of it as a hyperbolic surface can be constructed in 3-space.

A truncated icosahedron as a polyhedron and a ball	The Euclidean hexagonal tiling colored as truncated triangular tiling	A paper construction of a hyperbolic soccerball

Dual tiling

The dual tiling is called a heptakis heptagonal tiling, named for being constructible as a heptagonal tiling with every heptagon divided into seven triangles by the center point.

Related tilings

This hyperbolic tiling is topologically related as a part of sequence of uniform truncated polyhedra with vertex configurations (n.6.6), and [n,3] Coxeter group symmetry.

*n32 symmetry mutation of truncated tilings: n.6.6 v t e
Sym. *n42 [n,3]	Spherical				Euclid.	Compact		Parac.	Noncompact hyperbolic
Sym. *n42 [n,3]	*232 [2,3]	*332 [3,3]	*432 [4,3]	*532 [5,3]	*632 [6,3]	*732 [7,3]	*832 [8,3]...	*∞32 [∞,3]	[12i,3]	[9i,3]	[6i,3]
Truncated figures
Config.	2.6.6	3.6.6	4.6.6	5.6.6	6.6.6	7.6.6	8.6.6	∞.6.6	12i.6.6	9i.6.6	6i.6.6
n-kis figures
Config.	V2.6.6	V3.6.6	V4.6.6	V5.6.6	V6.6.6	V7.6.6	V8.6.6	V∞.6.6	V12i.6.6	V9i.6.6	V6i.6.6

From a Wythoff construction there are eight hyperbolic uniform tilings that can be based from the regular heptagonal tiling.

Drawing the tiles colored as red on the original faces, yellow at the original vertices, and blue along the original edges, there are 8 forms.

Uniform heptagonal/triangular tilings v t e
Symmetry: $[7,3], (*732)$							$[7,3] +, (732)$


${7,3}$	$t{7,3}$	$r{7,3}$	$t{3,7}$	${3,7}$	$rr{7,3}$	$tr{7,3}$	$sr{7,3}$
Uniform duals


$V7 3$	$V3.14.14$	$V3.7.3.7$	$V6.6.7$	$V3 7$	$V3.4.7.4$	$V4.6.14$	$V3.3.3.3.7$

In popular culture

This tiling features prominently in HyperRogue.

References

^ HOW TO BUILD YOUR OWN HYPERBOLIC SOCCER BALL MODEL

John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, The Symmetries of Things 2008, ISBN 978-1-56881-220-5 (Chapter 19, The Hyperbolic Archimedean Tessellations)
"Chapter 10: Regular honeycombs in hyperbolic space". The Beauty of Geometry: Twelve Essays. Dover Publications. 1999. ISBN 0-486-40919-8. LCCN 99035678.

External links

[1] HOW TO BUILD YOUR OWN HYPERBOLIC SOCCER BALL MODEL

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