Definition of “triangle” - English Dictionary

british dictionary

“triangle” in British English

See all translations

trianglenoun [ C ]

uk /ˈtraɪ.æŋ.ɡəl/ us /ˈtraɪ.æŋ.ɡəl/

B2 a flat shape with three straight sides:

an equilateral/isosceles triangle

anything that has three straight sides:

Which earrings did you buy in the end - the triangles or the circles?

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

US UK set square a flat piece of metal or plastic in the shape of a triangle with one angle of 90°, used for drawing angles

also frame a three-sided frame for arranging the balls at the start of a game of billiards, pool, etc.

More 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.

(Definition of “triangle” from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

“triangle” in American English

See all translations

trianglenoun [ C ]

us /ˈtrɑɪˌæŋ·ɡəl/

mathematics a flat shape with three straight sides:

Her earrings were in the shape of triangles.

music A triangle is also a musical instrument consisting of a thin metal bar having three sides, which makes a high sound when held up in the air and hit with a metal bar.

(Definition of “triangle” from the Cambridge Academic Content Dictionary © Cambridge University Press)