Longman Dictionary of Contemporary English homepage

Date: 1300-1400
Language: Latin
Origin: triangulum, from tri- ( TRI-) + angulus 'angle'

triangle

noun
     
triangle
Related topics: Music, Shapes, Patterns, Maths, Tools
tri‧an‧gle [countable]
1HM a flat shape with three straight sides and three angles
2CF something that is shaped like a triangle:
a triangle of land
3APM a musical instrument made of metal bent into the shape of a triangle. You hit it with a metal stick to make a ringing sound.
4 American EnglishHM a flat plastic object with three sides that has one angle of 90° and is used for drawing angles [= set-square British English]

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