Telo ograničeno sa četiri podudarna ravnostrana trougla (jedno od pet pravilnih geometrijskih tela: tetraedar, heksaedar, oktaedar, dodekaedar, ikosiedar).
tetrahedron / tetrəhiːdrən /
Množina reči tetrahedron je tetrahedrons.
ETYM Tetra- + Greek hedra seat, base, from hizein to sit.
Any polyhedron having four plane faces.
Four-sided solid figure. In geometry, a solid figure (polyhedron) with four triangular faces; that is, a pyramid on a triangular base. A regular tetrahedron has equilateral triangles as its faces.
In chemistry and crystallography, tetrahedra describe the shapes of some molecules and crystals; for example, the carbon atoms in a crystal of diamond are arranged in space as a set of interconnected regular tetrahedra.