Uniform 4-polytope
| Tetrahedral prism
|
Schlegel diagram
|
| Type |
Prismatic uniform 4-polytope
|
| Uniform index |
48
|
| Schläfli symbol |
t{2,3,3} = {}×{3,3} = h{4,3}×{}
s{2,4}×{}
sr{2,2}×{}
|
| Coxeter diagram |
    =  
|
| Cells |
2 (3.3.3)
4 (3.4.4)
|
| Faces |
8 {3}
6 {4}
|
| Edges |
16
|
| Vertices |
8
|
| Vertex configuration |
Equilateral-triangular pyramid
|
| Dual |
Tetrahedral bipyramid
|
| Symmetry group |
[3,3,2], order 48
[4,2+,2], order 16
[(2,2)+,2], order 8
|
| Properties |
convex
|
Net
|
In geometry, a tetrahedral prism is a convex uniform 4-polytope. This 4-polytope has 6 polyhedral cells: 2 tetrahedra connected by 4 triangular prisms. It has 14 faces: 8 triangular and 6 square. It has 16 edges and 8 vertices.
It is one of 18 uniform polyhedral prisms created by using uniform prisms to connect pairs of parallel Platonic solids and Archimedean solids.
Structure
The tetrahedral prism is bounded by two tetrahedra and four triangular prisms. The triangular prisms are joined to each other via their square faces, and are joined to the two tetrahedra via their triangular faces.
Projections
The tetrahedron-first orthographic projection of the tetrahedral prism into 3D space has a tetrahedral projection envelope. Both tetrahedral cells project onto this tetrahedron, while the triangular prisms project to its faces.
The triangular-prism-first orthographic projection of the tetrahedral prism into 3D space has a projection envelope in the shape of a triangular prism. The two tetrahedral cells are projected onto the triangular ends of the prism, each with a vertex that projects to the center of the respective triangular face. An edge connects these two vertices through the center of the projection. The prism may be divided into three non-uniform triangular prisms that meet at this edge; these 3 volumes correspond with the images of three of the four triangular prismic cells. The last triangular prismic cell projects onto the entire projection envelope.
The edge-first orthographic projection of the tetrahedral prism into 3D space is identical to its triangular-prism-first parallel projection.
The square-face-first orthographic projection of the tetrahedral prism into 3D space has a cuboidal envelope (see diagram). Each triangular prismic cell projects onto half of the cuboidal volume, forming two pairs of overlapping images. The tetrahedral cells project onto the top and bottom square faces of the cuboid.
