geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...

, a dodecahedral prism is a convex

uniform 4-polytope In geometry, a uniform 4-polytope (or uniform polychoron) is a 4-dimensional polytope which is vertex-transitive and whose cells are uniform polyhedra, and faces are regular polygons. There are 47 non-prismatic convex uniform 4-polytopes. Th ...

. This

4-polytope In geometry, a 4-polytope (sometimes also called a polychoron, polycell, or polyhedroid) is a four-dimensional polytope. It is a connected and closed figure, composed of lower-dimensional polytopal elements: vertices, edges, faces (polygons), an ...

has 14 polyhedral cells: 2

dodecahedra In geometry, a dodecahedron (Greek , from ''dōdeka'' "twelve" + ''hédra'' "base", "seat" or "face") or duodecahedron is any polyhedron with twelve flat faces. The most familiar dodecahedron is the regular dodecahedron with regular pentagon ...

connected by 12

pentagonal prism In geometry, the pentagonal prism is a prism with a pentagonal base. It is a type of heptahedron with seven faces, fifteen edges, and ten vertices. As a semiregular (or uniform) polyhedron If faces are all regular, the pentagonal prism is ...

s. It has 54 faces: 30 squares and 24 pentagons. It has 80 edges and 40 vertices. It can be constructed by creating two coinciding dodecahedra in 3-space, and translating each copy in opposite perpendicular directions in 4-space until their separation equals their edge length. It is one of 18 convex uniform polyhedral prisms created by using uniform

prism Prism usually refers to: * Prism (optics), a transparent optical component with flat surfaces that refract light * Prism (geometry), a kind of polyhedron Prism may also refer to: Science and mathematics * Prism (geology), a type of sedimentary ...

s to connect pairs of parallel

Platonic solid In geometry, a Platonic solid is a convex, regular polyhedron in three-dimensional Euclidean space. Being a regular polyhedron means that the faces are congruent (identical in shape and size) regular polygons (all angles congruent and all e ...

s or Archimedean solids.

Alternative names

# Dodecahedral dyadic prism Norman W. Johnson # Dodecahedral hyperprism

Images

File:Hyperprisme dodécaèdre.gif File:Dodecahedral hyperprism Schlegel.png , Transparent

Schlegel diagram In geometry, a Schlegel diagram is a projection of a polytope from \mathbb^d into \mathbb^ through a point just outside one of its facets. The resulting entity is a polytopal subdivision of the facet in \mathbb^ that, together with the orig ...

File:Dodecahedral hyperprism.png , An orthographic projection with a wireframe model and has half of the pentagonal faces colored to show the two dodecahedra. The dodecahedra are regular, but look flattened because of the projection and direction of viewing.

Structure

The dodecahedral prism consists of two dodecahedra connected to each other via 12

pentagonal In geometry, a pentagon (from the Greek πέντε ''pente'' meaning ''five'' and γωνία ''gonia'' meaning ''angle'') is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°. A pentagon may be simpl ...

prisms. The pentagonal prisms are joined to each other via their square faces.

Projections

The pentagonal-prism-first orthographic projection of the dodecahedral prism into 3D space has a

decagonal In geometry, a decagon (from the Greek δέκα ''déka'' and γωνία ''gonía,'' "ten angles") is a ten-sided polygon or 10-gon.. The total sum of the interior angles of a simple decagon is 1440°. A self-intersecting ''regular decagon'' i ...

envelope (see diagram). Two of the pentagonal prisms project to the center of this volume, each surrounded by 5 other pentagonal prisms. They form two sets (each consisting of a central pentagonal prism surrounded by 5 other non-uniform pentagonal prisms) that cover the volume of the decagonal prism twice. The two dodecahedra project onto the decagonal faces of the envelope. The dodecahedron-first orthographic projection of the dodecahedral prism into 3D space has a dodecahedral envelope. The two dodecahedral cells project onto the entire volume of this envelope, while the 12 decagonal prismic cells project onto its 12 pentagonal faces.

External links

* * {{KlitzingPolytopes, polychora.htm, 4D uniform polytopes (polychora), x o3o5x - dope 4-polytopes