Definition of "triangle" []

  • The plane figure formed by connecting three points not in a straight line by straight line segments; a three-sided polygon. (noun)
  • Something shaped like such a figure: a triangle of land. (noun)
  • Any of various flat, three-sided drawing and drafting guides, used especially to draw straight lines at specific angles. (noun)
  • Music A percussion instrument consisting of a piece of metal in the shape of a triangle open at one angle. (noun)
  • A relationship involving three people, especially a ménage à trois. (noun)
  • 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: 1⁄2base × height (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

  • Any object shaped like a triangle (noun)
  • Any situation involving three parties or points of view (noun)
  • A percussion instrument consisting of a sonorous metal bar bent into a triangular shape, beaten with a metal stick (noun)
  • A group of three (noun) (c) HarperCollins Publishers Ltd 2016

Use "triangle" in a sentence
  • "After a long series of experiments, guided by his ideas of the genesis of geometric figures, Séguin became aware that the triangle is the figure most easily drawn."
  • "The Moslems, I am told, cut three locks – a triangle is a favourite Moslem tattoo pattern."
  • "Because when I go out on head coaching interviews and if I mention the word 'triangle,' it makes general managers and owners cringe."