triangle

noun

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

Illustration of triangle

Illustration of triangle
  • 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 But how to understand the pileup of body parts and overlapping planes that form a vast triangle at the center of the picture? Sebastian Smee, Washington Post, 15 Mar. 2024 Chelsea Blackwell never considered revisiting the other point of her Love Is Blind season 6 love triangle. Sydney Bucksbaum, EW.com, 14 Mar. 2024 Peoria police say a love triangle sparked the most recent foam incident in February. The Arizona Republic, 14 Mar. 2024 To create these mountain-like triangles, simply tape off the pattern and paint them in two colors. Jessica Bennett, Better Homes & Gardens, 13 Mar. 2024 Deneb, Vega, and Altair are the three stars that make up the triangle. Elizabeth Gamillo, Discover Magazine, 5 Mar. 2024 The same pricing goes for Parade’s triangle, plunge, and star lace bralettes, too. Clara McMahon, Peoplemag, 25 Feb. 2024 So begins a tense pseudo-romantic triangle in which the three of them start spending time together, Samet silently envious of the attention Nuray shows Kenan. Tim Grierson, Los Angeles Times, 22 Feb. 2024 In Netflix’s Irish Wish, directed by Falling for Christmas’ Janeen Damian, Lohan stars as Maddie, a shy book editor who finds herself in a love triangle after traveling to Ireland for her best friend’s wedding to Paul — who Maddie believes to be the love of her life. Bailey Richards, Peoplemag, 6 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'triangle.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

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

Dictionary Entries Near triangle

Cite this Entry

“Triangle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/triangle. Accessed 28 Mar. 2024.

Kids Definition

triangle

noun
tri·​an·​gle ˈtrī-ˌaŋ-gəl How to pronounce triangle (audio)
1
: a figure that has three sides and three angles : a polygon that has three sides
2
: a percussion instrument made of a steel rod bent into a triangle open at one corner which is played by striking with a metal rod
3
: a drafting instrument consisting of a thin flat right-angled triangle

Medical Definition

triangle

noun
tri·​an·​gle ˈtrī-ˌaŋ-gəl How to pronounce triangle (audio)
: a three-sided region or space and especially an anatomical one see anterior triangle, carotid triangle, femoral triangle, posterior triangle, suboccipital triangle

More from Merriam-Webster on triangle

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