heptahedron
Definition
Noun (Mathematics): A heptahedron is a polyhedron with seven faces. It is a three-dimensional geometric solid composed of seven planar surfaces.
Usage Examples
- (A cube has six faces, whereas a heptahedron has seven.)
- (The student built a solid shape with seven faces.)
- (A cube modified by removing a vertex can result in a shape with seven faces.)
Advanced Usage
Regular heptahedron: A hypothetical heptahedron with all faces being congruent regular polygons. No such convex regular heptahedron exists, but some non-convex or irregular forms can be constructed.
- Mathematicians have studied whether a regular heptahedron is possible, concluding it is not. (No convex polyhedron with seven identical regular polygonal faces exists.)
Self-intersecting heptahedron: A heptahedron that may have faces that intersect each other, such as certain star polyhedra.
- The small stellated dodecahedron is not a heptahedron, but some self-intersecting forms have seven faces. (Complex polyhedra can have seven faces that cross each other.)
Variants and Related Words
Heptahedral (adj): Relating to or having the form of a heptahedron.
- The crystal exhibited a heptahedral shape. (The crystal had seven faces.)
Heptahedra (plural noun): The plural form of heptahedron.
- Several heptahedra were displayed in the museum. (Multiple polyhedra with seven faces were shown.)
Synonyms
- Seven-faced polyhedron: A more descriptive term for a heptahedron.
- A heptahedron is simply a seven-faced polyhedron. (A polyhedron with exactly seven faces.)
Related Idioms