Order-7 heptagrammic tiling

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Order-7 heptagrammic tiling
Hyperbolic tiling 7-2 7.png
Poincaré disk model of the hyperbolic plane
Type Hyperbolic regular tiling
Vertex configuration (7/2)7
Schläfli symbol {7/2,7}
Wythoff symbol 7 | 7/2 2
Coxeter diagram CDel node 1.pngCDel 7.pngCDel rat.pngCDel 2x.pngCDel node.pngCDel 7.pngCDel node.png
Symmetry group [7,3], (*732)
Dual Heptagrammic-order heptagonal tiling
Properties Vertex-transitive, edge-transitive, face-transitive

In geometry, the order-7 heptagrammic tiling is a tiling of the hyperbolic plane by overlapping heptagrams.

Contents

Description

This tiling is a regular star-tiling, and has Schläfli symbol of {7/2,7}. The heptagrams forming the tiling are of type {7/2}, Obtuse heptagram.svg . The overlapping heptagrams subdivide the hyperbolic plane into isosceles triangles, 14 of which form each heptagram.

Each point of the hyperbolic plane that does not lie on a heptagram edge belongs to the central heptagon of one heptagram, and is in one of the points of exactly one other heptagram. The winding number of each heptagram around its points is one, and the winding number around the central heptagon is two, so adding these two numbers together, each point of the plane is surrounded three times; that is, the density of the tiling is 3.

In the Euclidean plane, a heptagram of type {7/2} would have angles of 3π/7 at its vertices, but in the hyperbolic plane heptagrams can have the sharper vertex angle 2π/7 that is needed to make exactly seven other heptagrams meet up at the center of each heptagram of the tiling.

It has the same vertex arrangement as the regular order-7 triangular tiling, {3,7}. The full set of edges coincide with the edges of a heptakis heptagonal tiling. The valance 6 vertices in this tiling are false-vertices in the heptagrammic one caused by crossed edges.

Order-7 triangular tiling.svg Heptakis heptagonal tiling.svg

It is related to a Kepler-Poinsot polyhedron, the small stellated dodecahedron, {5/2,5}, which is polyhedron and a density-3 regular star-tiling on the sphere:

Small stellated dodecahedron tiling.png

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<span class="mw-page-title-main">Triangular tiling</span> Regular tiling of the plane

In geometry, the triangular tiling or triangular tessellation is one of the three regular tilings of the Euclidean plane, and is the only such tiling where the constituent shapes are not parallelogons. Because the internal angle of the equilateral triangle is 60 degrees, six triangles at a point occupy a full 360 degrees. The triangular tiling has Schläfli symbol of {3,6}.

<span class="mw-page-title-main">Small cubicuboctahedron</span>

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<span class="mw-page-title-main">Honeycomb (geometry)</span> Tiling of 3-or-more dimensional euclidian or hyperbolic space

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<span class="mw-page-title-main">Order-7 triangular tiling</span>

In geometry, the order-7 triangular tiling is a regular tiling of the hyperbolic plane with a Schläfli symbol of {3,7}.

<span class="mw-page-title-main">Triheptagonal tiling</span>

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<span class="mw-page-title-main">Truncated triheptagonal tiling</span> Semiregular tiling of the hyperbolic plane

In geometry, the truncated triheptagonal tiling is a semiregular tiling of the hyperbolic plane. There is one square, one hexagon, and one tetradecagon (14-sides) on each vertex. It has Schläfli symbol of tr{7,3}.

<span class="mw-page-title-main">Truncated heptagonal tiling</span>

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<span class="mw-page-title-main">Rhombitriheptagonal tiling</span> Geometric tiling

In geometry, the rhombitriheptagonal tiling is a semiregular tiling of the hyperbolic plane. At each vertex of the tiling there is one triangle and one heptagon, alternating between two squares. The tiling has Schläfli symbol rr{7, 3}. It can be seen as constructed as a rectified triheptagonal tiling, r{7,3}, as well as an expanded heptagonal tiling or expanded order-7 triangular tiling.

<span class="mw-page-title-main">Snub triheptagonal tiling</span>

In geometry, the order-3 snub heptagonal tiling is a semiregular tiling of the hyperbolic plane. There are four triangles and one heptagon on each vertex. It has Schläfli symbol of sr{7,3}. The snub tetraheptagonal tiling is another related hyperbolic tiling with Schläfli symbol sr{7,4}.

<span class="mw-page-title-main">Truncated order-7 triangular tiling</span>

In geometry, the order-7 truncated triangular tiling, sometimes called the hyperbolic soccerball, 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 with heptagons in place of pentagons. It has Schläfli symbol of t{3,7}.

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<span class="mw-page-title-main">Snub trioctagonal tiling</span>

In geometry, the order-3 snub octagonal tiling is a semiregular tiling of the hyperbolic plane. There are four triangles, one octagon on each vertex. It has Schläfli symbol of sr{8,3}.

<span class="mw-page-title-main">Rhombitrioctagonal tiling</span> Semiregular tiling of the hyperbolic plane

In geometry, the rhombitrioctagonal tiling is a semiregular tiling of the hyperbolic plane. At each vertex of the tiling there is one triangle and one octagon, alternating between two squares. The tiling has Schläfli symbol rr{8,3}. It can be seen as constructed as a rectified trioctagonal tiling, r{8,3}, as well as an expanded octagonal tiling or expanded order-8 triangular tiling.

<span class="mw-page-title-main">Heptagrammic-order heptagonal tiling</span>

In geometry, the heptagrammic-order heptagonal tiling is a regular star-tiling of the hyperbolic plane. It has Schläfli symbol of {7,7/2}. The vertex figure heptagrams are {7/2}, . The heptagonal faces overlap with density 3.

In the geometry of hyperbolic 3-space, the order-7-3 triangular honeycomb is a regular space-filling tessellation with Schläfli symbol {3,7,3}.

In the geometry of hyperbolic 3-space, the order-infinite-3 triangular honeycomb is a regular space-filling tessellation with Schläfli symbol {3,∞,3}.

References

See also