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 c ...

, a decahedron is a polyhedron with ten faces. There are 32300 topologically distinct decahedra, and none are regular, so this name does not identify a specific type of polyhedron except for the number of faces. Some decahedra have regular faces: * Octagonal prism (uniform 8- prism) * Square antiprism (uniform 4- antiprism) * Square cupola (

Johnson solid In geometry, a Johnson solid is a strictly convex polyhedron each face of which is a regular polygon. There is no requirement that each face must be the same polygon, or that the same polygons join around each vertex. An example of a Johns ...

4) * Pentagonal bipyramid (Johnson solid 13, 5- bipyramid) *

Augmented pentagonal prism In geometry, the augmented pentagonal prism is one of the Johnson solids (). As the name suggests, it can be constructed by augmenting a pentagonal prism by attaching a square pyramid In geometry, a square pyramid is a pyramid having a squar ...

(Johnson solid 52) The decahedra with irregular faces include: * Pentagonal trapezohedron (5- trapezohedron, antiprism dual) often used as a die in role playing games, known as d10 * Enneagonal pyramid (9-

pyramid A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrila ...

) * Ten of diamonds decahedron - a space-filling polyhedron with D_2d symmetry.

References

External links

* {{Polyhedra Polyhedra