decahedron

{{Short description|Polyhedron with 10 faces}}

File:10 sided die.svg ]]

{{Commons category|Decahedra}}

In geometry, a decahedron is a polyhedron with ten faces. There are 32300 topologically distinct decahedra,Gerard Michon: [http://www.numericana.com/data/polyhedra.htm Counting Polyhedra]{{cite OEIS|A000944}} 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 4)
• Pentagonal bipyramid (Johnson solid 13, 5-bipyramid)
• Augmented pentagonal prism (Johnson solid 52)

The decahedra with irregular faces include:

• Pentagonal trapezohedron (5-trapezohedron, antiprism dual){{snd}} often used as a die in role playing games, known as a d10
• Truncated square trapezohedron
• Enneagonal pyramid (9-pyramid)
• Ten of diamonds decahedron - a space-filling polyhedron with D_2d symmetry.