39 relations: Convex polytope, Coxeter element, Coxeter group, Coxeter–Dynkin diagram, E7 (mathematics), Edge (geometry), Emanuel Lodewijk Elte, Face (geometry), Geometry, Gosset–Elte figures, Harold Scott MacDonald Coxeter, Hyperplane, List of E7 polytopes, Octadecagon, Petrie polygon, Projection (linear algebra), Rectification (geometry), Rectified 6-simplexes, Schläfli symbol, Simple Lie group, Tetrahedron, Triangle, Uniform 2 k1 polytope, Uniform 7-polytope, Uniform honeycomb, Uniform polytope, Vertex (geometry), Vertex figure, Wythoff construction, 1 32 polytope, 2 21 polytope, 2 31 polytope, 3 21 polytope, 3 31 honeycomb, 5-cell, 5-orthoplex, 5-simplex, 6-demicube, 6-simplex.

## Convex polytope

A convex polytope is a special case of a polytope, having the additional property that it is also a convex set of points in the n-dimensional space Rn.

New!!: 2 31 polytope and Convex polytope ·

## Coxeter element

In mathematics, the Coxeter number h is the order of a Coxeter element of an irreducible Coxeter group.

New!!: 2 31 polytope and Coxeter element ·

## Coxeter group

In mathematics, a Coxeter group, named after H. S. M. Coxeter, is an abstract group that admits a formal description in terms of reflections (or kaleidoscopic mirrors).

New!!: 2 31 polytope and Coxeter group ·

## Coxeter–Dynkin diagram

In geometry, a Coxeter–Dynkin diagram (or Coxeter diagram, Coxeter graph) is a graph with numerically labeled edges (called branches) representing the spatial relations between a collection of mirrors (or reflecting hyperplanes).

New!!: 2 31 polytope and Coxeter–Dynkin diagram ·

## E7 (mathematics)

In mathematics, E7 is the name of several closely related Lie groups, linear algebraic groups or their Lie algebras e7, all of which have dimension 133; the same notation E7 is used for the corresponding root lattice, which has rank 7.

New!!: 2 31 polytope and E7 (mathematics) ·

## Edge (geometry)

In geometry, an edge is a particular type of line segment joining two vertices in a polygon, polyhedron, or higher-dimensional polytope.

New!!: 2 31 polytope and Edge (geometry) ·

## Emanuel Lodewijk Elte

Emanuel Lodewijk Elte (16 March 1881, Amsterdam – 9 April 1943, Sobibór) at joodsmonument.nl was a Dutch mathematician.

New!!: 2 31 polytope and Emanuel Lodewijk Elte ·

## Face (geometry)

In solid geometry, a face is a flat (planar) surface that forms part of the boundary of a solid object; a three-dimensional solid bounded exclusively by flat faces is a polyhedron.

New!!: 2 31 polytope and Face (geometry) ·

## Geometry

Geometry (from the γεωμετρία; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.

New!!: 2 31 polytope and Geometry ·

## Gosset–Elte figures

In geometry, the Gosset–Elte figures, named by Coxeter after Thorold Gosset and E. L. Elte, are a group of uniform polytopes which are not regular, generated by a Wythoff construction with mirrors all related by order-2 and order-3 dihedral angles.

New!!: 2 31 polytope and Gosset–Elte figures ·

## Harold Scott MacDonald Coxeter

Harold Scott MacDonald "Donald" Coxeter, FRS, FRSC, (February 9, 1907 – March 31, 2003) was a British-born Canadian geometer.

New!!: 2 31 polytope and Harold Scott MacDonald Coxeter ·

## Hyperplane

In geometry a hyperplane is a subspace of one dimension less than its ambient space.

New!!: 2 31 polytope and Hyperplane ·

## List of E7 polytopes

In 7-dimensional geometry, there are 127 uniform polytopes with E7 symmetry.

New!!: 2 31 polytope and List of E7 polytopes ·

## Octadecagon

An octadecagon (or octakaidecagon) is a polygon with 18 sides and 18 vertices.

New!!: 2 31 polytope and Octadecagon ·

## Petrie polygon

In geometry, a Petrie polygon for a regular polytope of n dimensions is a skew polygon such that every (n-1) consecutive sides (but no n) belong to one of the facets.

New!!: 2 31 polytope and Petrie polygon ·

## Projection (linear algebra)

In linear algebra and functional analysis, a projection is a linear transformation P from a vector space to itself such that.

New!!: 2 31 polytope and Projection (linear algebra) ·

## Rectification (geometry)

In Euclidean geometry, rectification or complete-truncation is the process of truncating a polytope by marking the midpoints of all its edges, and cutting off its vertices at those points.

New!!: 2 31 polytope and Rectification (geometry) ·

## Rectified 6-simplexes

In six-dimensional geometry, a rectified 6-simplex is a convex uniform 6-polytope, being a rectification of the regular 6-simplex.

New!!: 2 31 polytope and Rectified 6-simplexes ·

## Schläfli symbol

In geometry, the Schläfli symbol is a notation of the form that defines regular polytopes and tessellations.

New!!: 2 31 polytope and Schläfli symbol ·

## Simple Lie group

In group theory, a simple Lie group is a connected non-abelian Lie group G which does not have nontrivial connected normal subgroups.

New!!: 2 31 polytope and Simple Lie group ·

## Tetrahedron

In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons) is a polyhedron composed of four triangular faces, three of which meet at each corner or vertex.

New!!: 2 31 polytope and Tetrahedron ·

## Triangle

A triangle is a polygon with three edges and three vertices.

New!!: 2 31 polytope and Triangle ·

## Uniform 2 k1 polytope

In geometry, 2k1 polytope is a uniform polytope in n dimensions (n.

New!!: 2 31 polytope and Uniform 2 k1 polytope ·

## Uniform 7-polytope

In seven-dimensional geometry, a 7-polytope is a polytope contained by 6-polytope facets.

New!!: 2 31 polytope and Uniform 7-polytope ·

## Uniform honeycomb

In geometry, a uniform honeycomb or uniform tessellation or infinite uniform polytope, is a vertex-transitive honeycomb made from uniform polytope facets.

New!!: 2 31 polytope and Uniform honeycomb ·

## Uniform polytope

A uniform polytope of dimension three or higher is a vertex-transitive polytope bounded by uniform facets.

New!!: 2 31 polytope and Uniform polytope ·

## Vertex (geometry)

In geometry, a vertex (plural vertices) is a special kind of point that describes the corners or intersections of geometric shapes.

New!!: 2 31 polytope and Vertex (geometry) ·

## Vertex figure

In geometry a vertex figure is, broadly speaking, the figure exposed when a corner of a polyhedron or polytope is sliced off.

New!!: 2 31 polytope and Vertex figure ·

## Wythoff construction

In geometry, a Wythoff construction, named after mathematician Willem Abraham Wythoff, is a method for constructing a uniform polyhedron or plane tiling.

New!!: 2 31 polytope and Wythoff construction ·

## 1 32 polytope

In 7-dimensional geometry, 132 is a uniform polytope, constructed from the E7 group.

New!!: 2 31 polytope and 1 32 polytope ·

## 2 21 polytope

In 6-dimensional geometry, the 221 polytope is a uniform 6-polytope, constructed within the symmetry of the E6 group.

New!!: 2 31 polytope and 2 21 polytope ·

## 2 31 polytope

In 7-dimensional geometry, 231 is a uniform polytope, constructed from the E7 group.

New!!: 2 31 polytope and 2 31 polytope ·

## 3 21 polytope

In 7-dimensional geometry, the 321 polytope is a uniform 7-polytope, constructed within the symmetry of the E7 group.

New!!: 2 31 polytope and 3 21 polytope ·

## 3 31 honeycomb

In 7-dimensional geometry, the 331 honeycomb is a uniform honeycomb, also given by Schläfli symbol and is composed of 321 and 7-simplex facets, with 56 and 576 of them respectively around each vertex.

New!!: 2 31 polytope and 3 31 honeycomb ·

## 5-cell

In geometry, the 5-cell is a four-dimensional object bounded by 5 tetrahedral cells.

New!!: 2 31 polytope and 5-cell ·

## 5-orthoplex

In five-dimensional geometry, a 5-orthoplex, or 5-cross polytope, is a five-dimensional polytope with 10 vertices, 40 edges, 80 triangle faces, 80 tetrahedron cells, 32 5-cell 4-faces.

New!!: 2 31 polytope and 5-orthoplex ·

## 5-simplex

In five-dimensional geometry, a 5-simplex is a self-dual regular 5-polytope.

New!!: 2 31 polytope and 5-simplex ·

## 6-demicube

In geometry, a 6-demicube or demihexteract is a uniform 6-polytope, constructed from a 6-cube (hexeract) with alternated vertices truncated.

New!!: 2 31 polytope and 6-demicube ·

## 6-simplex

In geometry, a 6-simplex is a self-dual regular 6-polytope.

New!!: 2 31 polytope and 6-simplex ·

## Redirects here:

Gosset 2 31 polytope, Rectified 2 31 polytope.