tri·​an·​gle | \ ˈtrī-ˌaŋ-gəl How to pronounce triangle (audio) \

Definition of triangle

1 : a polygon having three sides — compare spherical triangle
2a : 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

Illustration of triangle

Illustration of triangle

triangle 1: 1 equilateral, 2 acute, 3 obtuse, 4 scalene, 5 isosceles, 6 right triangle

Examples of triangle in a Sentence

She cut the sandwiches into triangles.

Recent Examples on the Web

An unsuspecting love triangle ensues, and the waves of betrayal and passion left the audience, which included Charlie Heaton, Lena Hall, and Kate Walsh, entranced. Zachary Weiss, Vogue, "Keira Knightley Smoldered at the New York Premiere of Her Post-War Drama The Aftermath," 14 Mar. 2019 In the candid pic, Kardashian is wearing a bubblegum pink bodysuit and holding North, who is wearing a bright yellow triangle bikini, on her lap. Andrea Park, Allure, "Kim Kardashian Is Being Mom-Shamed by Some Assholes on Instagram for Letting North Wear a Bikini," 30 Aug. 2018 The swimwear collection ranges from crop and triangle bikini tops to French cut bikini bottoms, one-piece swimsuits and fishnet cover-ups in various neon and neutral colors. Lisa Lockwood | Wwd,, "Joan Smalls designs swimwear, intimate apparel for Smart & Sexy," 21 May 2018 But Kevin Smith also managed a somewhat nuanced exploration of friendship and art, as well as of contemporary romantic standards in his rejiggering of the love triangle. Vogue, "The 55 Best Romantic Comedies of All Time," 1 Feb. 2019 The Favorite, director Yorgos Lanthimos’s dark, comic depiction of a love triangle involving Queen Anne, and Mary Poppins Returns. Adam Rathe, Town & Country, "How the Costumes in The Favourite Help Tell the Story of Queen Anne," 21 Nov. 2018 Each drawing sits at the apex of a triangle composed of rabbit fur and photo scans of the skins, all of which questions hierarchies of representation and histories of invasiveness, including our own. Gayle Clemans, The Seattle Times, "‘The Veil’ exhibition at Bridge Productions spans ideas of what’s seen and unseen," 7 Aug. 2018 When the gay community was facing the AIDS crisis, a group of artists reappropriated the symbol of the pink triangle that the Nazi regime had forced gay people to wear. Sonia K. Katyal,, "The sudden rush of vulgar trademarks," 23 June 2018 Place 1 wiener on shortest side of each triangle; roll up to opposite point. Cassie Armstrong,, "National Pigs in a Blanket Day: How to celebrate in Central Florida," 24 Apr. 2018

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.

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First Known Use of triangle

14th century, in the meaning defined at sense 1

History and Etymology for triangle

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

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Statistics for triangle

Last Updated

22 May 2019

Look-up Popularity

Time Traveler for triangle

The first known use of triangle was in the 14th century

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English Language Learners Definition of triangle

: 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


tri·​an·​gle | \ ˈtrī-ˌaŋ-gəl How to pronounce triangle (audio) \

Kids Definition of triangle

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


tri·​an·​gle | \ ˈtrī-ˌaŋ-gəl How to pronounce triangle (audio) \

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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More from Merriam-Webster on triangle

Rhyming Dictionary: Words that rhyme with triangle

Spanish Central: Translation of triangle

Nglish: Translation of triangle for Spanish Speakers

Britannica English: Translation of triangle for Arabic Speakers Encyclopedia article about triangle

Comments on triangle

What made you want to look up triangle? Please tell us where you read or heard it (including the quote, if possible).


a strong desire or propensity

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