bn:00076703n
Noun Concept
Categories: Prismatoid polyhedra, Individual graphs, Platonic solids, Pyramids and bipyramids, Deltahedra
EN
tetrahedron  0 20 polytope  12-point sphere  1 01 polytope  1 10 polytope
EN
Any polyhedron having four plane faces WordNet 3.0
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EN
In geometry, a tetrahedron, also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. Wikipedia
Four-sided polyhedron Wikidata
A polyhedron with four faces. OmegaWiki
A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids. Wiktionary