tetrahedron
/ˌtɛtrəˈhiːdrən
/noun (plural tetrahedra /ˌtɛtrəˈhiːdrə/ or tetrahedrons)
A solid having four plane triangular faces; a triangular pyramid.In particular he identified the five elements, fire, earth, air, water and celestial matter with the five regular solids, the tetrahedron, cube, octahedron, icosahedron and the dodecahedron....
- Plato believed that atoms have the shapes of regular polyhedra: cubes, tetrahedrons, octahedrons, and so on.
- The new structure consists of 20 small crystalline tetrahedrons - pyramids with four triangular sides - that fit together a bit like sections of an orange.
Derivatives
tetrahedral
- Klee's mountains, pyramidal in form, might suggest to some the tetrahedral silicate structures of rock-forming minerals, but this connection may not have been in the mind of the artist.
- By the 1880s Wislicenus was fully convinced of the tetrahedral carbon and promoted the design of experiments as a means of understanding the spatial arrangement of atoms in organic structures.
- In designing aircraft his use of tetrahedral structural elements inspired him to develop and patent a system of space frame architecture.
Origin
Late 16th century: from late Greek tetraedron, neuter (used as a noun) of tetraedros 'four-sided'.