Definition

1. Noun:
   • A polyhedron with ten plane faces: A "decahedron" is a three-dimensional geometric solid that has exactly ten flat polygonal faces. It is a specific type of polyhedron.

Usage

• The word "decahedron" is a technical term used primarily in geometry, mathematics, and related scientific fields. It names a specific class of shapes based on the number of their faces.

Examples

• Noun:
  • A regular decahedron is a theoretical shape where all ten faces are congruent regular polygons.
  • The crystal's structure approximated an irregular decahedron.
  • In their geometry class, the students constructed models of various polyhedra, including a decahedron.

Advanced Usage

• "Regular decahedron": While a decahedron is defined by having ten faces, a decahedron would theoretically have all faces as identical regular polygons and all vertices identical. Note: There is no Platonic solid (completely regular, convex polyhedron) with ten faces.
• The term is often used in combinatorial geometry and crystallography to describe specific molecular or structural forms.

Variants and Related Words

• Decahedral (adj): Having the form of a decahedron; pertaining to a decahedron.
  • The mineral exhibited a decahedral crystal habit.

Synonyms

• Ten-faced polyhedron: A descriptive synonym.
• Polyhedron: The general category to which a decahedron belongs.

Related Terms (Conceptual)

• Polyhedron: A solid figure with many plane faces, typically more than six.
• Dodecahedron: A polyhedron with twelve faces.
• Octahedron: A polyhedron with eight faces.
• The prefix "deca-" comes from Greek, meaning "ten."

Noun

1. any polyhedron having ten plane faces