triangle /ˈtraɪ.æŋ.ɡl̩/ noun [C]
B2 a flat shape with three straight sides:
» an equilateral/isosceles triangleThesaurus+: ↑Geometrical shapes , ↑Spherical, circular and annular objectsF0 anything that has three straight sides:
» Which earrings did you buy in the end - the triangles or the circles?Thesaurus+: ↑Geometrical shapes , ↑Spherical, circular and annular objectsF0 a musical instrument consisting of a thin metal bar bent into a triangle shape that is hit with a metal bar to make a sound
Thesaurus+: ↑Percussion instrumentsF0 US FOR SET SQUARE(Cf. ↑set square)
Thesaurus+: ↑Geometrical and mathematical instrumentsF0 (ALSO frame) a three-sided frame for arranging the balls at the start of a game of billiards, pool, etc.
Thesaurus+: ↑Snooker, pool and billiards• • •
Extra Examples:» Draw a perpendicular from the vertex of the triangle to its base.» A triangle is a shape with three sides.» The cloth was decorated with triangles of different colours.» We cut some triangles of cheese.» To make a star, put two triangles together.