Representations of A4

There is an obvious problem to visualize four dimensional polytopes. However, it is convenient to display projections on a two dimensional plane, the so-called Coxeter plane, where a huge amount of symmetry of the polytope is preserved. To make these projections more illustrative, first the three dimensional analouges are shown. The projections of the representations of A3 reappear as subgraphs in the projections of the representations of A4.

 

Tetrahedron

Octahedron

CUBOCTAHEDRON

Truncated Tetrahedron

TRuncated Octahedron


Now the projections of the four-dimensional polytopes are shown in the usual way. Additionally, it is stated what kind of three-dimensional boundaries are contained and how many of them meet at one single vertex.

A120

  • 120 vertices
  • 30 3d-boundaries
  • 150 2d-faces
  • 240 edges

The 30 boundaries split into:

  • 20 hexagonal prims
  • 10 truncated octahedra

The 150 faces split into:

  • 60 hexagons
  • 90 squares

On one vertex, there meet

  • two prims and
  • two truncated octahedra 

A60A

  • 60 vertices
  • 30 3d-boundaries
  • 120 2d-faces
  • 150 edges

The 30 3d-boundaries split into:

  • 10 triangular prisms
  • 10 hexagonal prisms
  • 5 truncated tetrahedra
  • 5 cuboctahedra

The 120 2d-faces split into:

  • 40 triangles
  • 60 squares
  • 20 hexagons

On one vertex, there meet 

  • one triangual prism
  • two hexagonal prisms
  • one cuboctahedron
  • one truncated tetrahedron

A60b

  • 60 vertices
  • 20 3d-boundaries
  • 80 2d-faces
  • 120 edges

The 20 boundaries split into:

  • 10 triangular prisms
  • 5 truncated tetrahedra
  • 5 truncated octahedra

The 120 2d-faces split into:

  • 20 triangles
  • 30 squares
  • 30 hexagons

On one vertex, there meet 

  • two truncated octahedron
  • one truncated tetrahedron
  • one triangular prism

A30

  • 30 vertices
  • 20 3d-boundaries
  • 80 2d-faces
  • 90 edges

The 20 3d-boundaries split into:

  • 5 octahedra
  • 5 cuboctahedra
  • 10 triangular prisms

The 80 2d-faces split into:

  • 50 triangles
  • 30 squares

On one vertex, there meet 

  • two triangular prisms
  • two cuboctahedra
  • one octahdron

A30b

  • 30 vertices
  • 10 3d-boundaries
  • 40 2d-faces
  • 60 edges

The 10 boundaries are truncated tetrahedra

 

The 30 faces split into:

  • 20 triangles
  • 20 hexagons

On one vertex, there meet four truncated tetrahedra

A20a

  • 20 vertices
  • 30 3d-boundaries
  • 70 2d-faces
  • 60 edges

The 30 boundaries split into:

  • 10 tetrahedra
  • 20 triangular prisms

The 150 faces split into:

  • 40 triangles
  • 30 squares

On one vertex, there meet

  • two tetrahedra and
  • six prisms 

A20b

  • 20 vertices
  • 10 3d-boundaries
  • 30 2d-faces
  • 40 edges

The 10 boundaries split into:

  • 5 tetrahedra
  • 5 truncated tetrahedra

The 30 2d-faces split into:

  • 20 triangles
  • 10 hexagons

On one vertex, there meet 

  • one tetrahedron
  • three truncated tetrahedra

A10

  • 10 vertices
  • 10 3d-boundaries
  • 30 2d-faces
  • 30 edges

The 10 boundaries split into:

  • 5 tetrahedra
  • 5 octahedra

The 30 faces are triangles

 

On one vertex, there meet 

  • two tetrahedra
  • three octahedra

A5

  • 5 vertices
  • 5 3d-boundaries
  • 10 2d-faces
  • 10 edges

The 5 boundaries tetrahedra

The 10 faces are triangles

 

On one vertex, there meet four tetrahedra