triangle

noun tri·an·gle \ ˈtrī-ˌaŋ-gəl \

Definition of triangle

1 :a polygon having three sides — compare spherical triangle
2 a :a percussion instrument consisting of a rod of steel bent into the form of a triangle open at one angle and sounded by striking with a small metal rod
b :a drafting instrument consisting of a thin flat right-angled triangle of wood or plastic with acute angles of 45 degrees or of 30 degrees and 60 degrees
3 :a situation in which one member of a couple is involved in a love affair with a third person

Examples of triangle in a Sentence

  1. She cut the sandwiches into triangles.

Recent Examples of triangle from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'triangle.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of triangle

Origin and Etymology of triangle

Middle English, from Anglo-French, from Latin triangulum, from neuter of triangulus triangular, from tri- + angulus angle



TRIANGLE Defined for English Language Learners

triangle

noun

Definition of triangle for English Language Learners

  • : a shape that is made up of three lines and three angles

  • : something that is shaped like a triangle

  • : a musical instrument that is made of a steel rod bent into the shape of a triangle and that you play by hitting with a metal rod


TRIANGLE Defined for Kids

triangle

noun tri·an·gle \ ˈtrī-ˌaŋ-gəl \

Definition of triangle for Students

1 :a flat geometric figure that has three sides and three angles
2 :something that has three sides and three angles
  • a triangle of land
3 :a musical instrument made of a steel rod bent in the shape of a triangle with one open angle

Medical Dictionary

triangle

noun tri·an·gle \ ˈtrī-ˌaŋ-gəl \

medical Definition of triangle

:a three-sided region or space and especially an anatomical one — see anterior triangle, carotid triangle, femoral triangle, posterior triangle, suboccipital triangle


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