- a closed plane figure having three sides and three angles.
- a flat triangular piece, usually of plastic, with straight edges, used in connection with a T square for drawing perpendicular lines, geometric figures, etc.
- any three-cornered or three-sided figure, object, or piece: a triangle of land.
- a musical percussion instrument that consists of a steel triangle, open at one corner, that is struck with a steel rod.
- a group of three; triad.
- a situation involving three persons, especially one in which two of them are in love with the third.
- (initial capital letter) Astronomy. the constellation Triangulum.
Origin of triangle
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for triangle
Each side of the triangle will measure five miles in width, a foot in depth, and nearly 307 miles in length.The 2013 Novel of the Year Is…
December 30, 2013
Legambiente has been warning of the equivalent of an environmental apocalypse in the triangle of death for years.Italy’s Triangle Of Death: Naples Residents Blame Child Cancer Rates On Mob Disposal Of Toxic Chemicals
Barbie Latza Nadeau
November 21, 2013
It was not conceived for what Tel Aviv has become and what the East Jerusalem-Ramallah-Hebron triangle will inevitably become.How The Israeli-Palestinian Peace Process Became The World's Greatest Bore
April 16, 2013
But she did like Ben Dahan: she said he made her rethink the “triangle.”Young Israeli Rightists Choose Between Ultra-Nationalists
January 2, 2013
The triangle is “like a rubber band wound up in a toy propeller,” Turner says.Romney’s Intrade Stock: Ready for a Bull Run?
August 14, 2012
When I asked the meaning of this, they showed me a triangle.Philothea
Lydia Maria Child
And he points out that within the triangle was the Svastika cross.The Non-Christian Cross
John Denham Parsons
This triangle they filled with a thinner stone carved with two lions.Buried Cities: Pompeii, Olympia, Mycenae
And directly in front of it are three other stars in the form of a triangle.The Chinese Fairy Book
They were alone, too, for the Gnomes had not entered the door of triangle.
- geometry a three-sided polygon that can be classified by angle, as in an acute triangle, or by side, as in an equilateral triangle. Sum of interior angles: 180°; area: 1/2 base × height
- any object shaped like a triangle
- any situation involving three parties or points of viewSee also eternal triangle
- music a percussion instrument consisting of a sonorous metal bar bent into a triangular shape, beaten with a metal stick
- a group of three
C14: from Latin triangulum (noun), from triangulus (adjective), from tri- + angulus corner
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for triangle
In the huts of witches all the instruments and implements are triangular. ["Handwörterbuch des deutschen Aberglaubens"]
Online Etymology Dictionary, © 2010 Douglas Harper
- A three-sided area, space, or structure.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- A closed geometric figure consisting of three sides.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with triangle
see eternal triangle.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.