# icosahedron

**IPA:** aɪkˈɑsʌhˈidrʌn

### noun

- (geometry) A polyhedron with twenty faces.
- (geometry, specifically) A regular icosahedron: one of the Platonic solids, all of whose faces are regular (equilateral) triangles

# Examples of "icosahedron" in Sentences

- The regular icosahedron is most popular.
- Compound of dodecahedron and icosahedron.
- The icosahedron is the dual of the dodecahedron.
- There are 3 uniform colorings of the icosahedron.
- This die is in the form of a regular icosahedron.
- It is the dual of the truncated great icosahedron.
- See the mathworld article on the great icosahedron.
- Its convex hull is a nonuniform truncated icosahedron.
- For example, the icosahedron is the dual of the dodecahedron.
- The icosahedron and the dodecahedron are Platonic solids with 30 edges.
- Join five equilateral triangles together and you have the first part of an icosahedron C.
- I've rolled the icosahedron and painted a few miniatures myself so it only raises my charisma to be accepted by that culture.
- The icosahedron is another of the five regular, or Platonic, bodies having all their sides, angles, and planes similar and equal.
- Only five shapes fit the bill: the tetrahedron, the cube, the octahedron, the icosahedron and the dodecahedron, the quintet known as the Platonic solids since Plato wrote about them in the Timaeus.
- Then, about 10 years ago, the mathematician Reidun Twarock developed a more general theory of the geometry of viruses based on the symmetries of the icosahedron, but using shapes in six dimensions, not three.
- The company receives more than 1 million applications a year and identifies the top candidates through a rigorous screening process that analyzes SAT scores, grade-point averages and their performance on tests with such questions as: "How many different ways can you color an icosahedron with one of three colors on each face?"