1. Definition

2. Practise

B2 a flat shape with three straight sides: an equilateral/isosceles triangleGeometrical shapesSpherical, circular and annular objects › anything that has three straight sides: Which earrings did you buy in the end - the triangles or the circles?Geometrical shapesSpherical, circular and annular objects › a musical instrument consisting of a thin metal bar bent into a triangle shape that is hit with a metal bar to make a soundPercussion instruments › US for set squareGeometrical and mathematical instruments › (also frame) a three-sided frame for arranging the balls at the start of a game of billiards, pool, etc.Snooker, pool and billiards

(Definition of triangle from the Cambridge Advanced Learners Dictionary & Thesaurus
© Cambridge University Press)

What is the pronunciation of triangle?
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