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

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Examples of triangle in a Sentence

She cut the sandwiches into triangles.

Recent Examples of triangle from the Web

Pythagorean triples are sets of numbers that correspond to the sides of right triangles.

— avery thompson, Popular Mechanics, "Researchers Discover Babylonian Tablet Is Ancient Trig Table," 25 Aug. 2017
Another lil’ love triangle playing out is though, with Lacey/Diggy/Dominique.

— ashley iaconetti, Cosmopolitan, "Bachelor in Paradise Recap: When Birthday Cake Goes Wrong," 23 Aug. 2017
After Sandy Leon singled to left, Bradley lined one to the triangle in center, scoring two and standing up into third.

— jimmy golen, courant.com, "Red Sox Beat Yankees, Move 5 Up In AL East," 20 Aug. 2017
Ten members of the offense celebrated the score by lining up in a triangle and toppling over as Agholor tossed an imaginary bowling ball at them.

— david murphy, Philly.com, "Eagles' rocky road at cornerback could lead to C.J. Smith | David Murphy," 4 Aug. 2017
But the defense argues that the three men were part of a love triangle.

— keith l. alexander, Washington Post, "Two roommates beaten to death, a third on trial for murder," 17 July 2017
Incremental increases in property tax revenue from development in the triangle are earmarked for things, such as debt service and financing public improvements, such as new streets and utility lines, in the TIF.

— mike nolan, Daily Southtown, "Orland Park checks out of apartment ownership," 11 July 2017
Start by folding the flag in a customary triangle manner.

— carly breit, Country Living, "Here's the Right Way to Dispose of a Worn American Flag," 11 July 2017
Hey, Phil Jackson: How did that triangle offense work out for the Knicks?

— bryce miller, sandiegouniontribune.com, "Lakers need to think 'long' during NBA rebuild," 4 July 2017

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

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First Known Use: 14th century

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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