isosceles

[ ahy-sos-uh-leez ]

/ aɪˈsɒs əˌliz /

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adjective

(of a straight-sided plane figure) having two sides equal: an isosceles triangle; an isosceles trapezoid.

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Origin of isosceles

1545–55; <Late Latin <Greek isoskelḗs with equal legs, equivalent to iso-iso- + skél(os) leg + -ēs adj. suffix

Words nearby isosceles

iso-reel, isorhythm, isorhythmic, isorrhea, isosbestic point, isosceles, isoseismal, isoseismic, isosexual, isosmotic, isosorbide dinitrate

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use isosceles in a sentence

It’s worth noting that many of these sets were rotations or reflections of each other, meaning if one of them was anti-isosceles then others were as well.
Can You Crack The Case Of The Crystal Key?|Zach Wissner-Gross (riddlercolumn@gmail.com)|May 28, 2021|FiveThirtyEight
If the distances between any two of these were the same, the entire set could not be anti-isosceles.
Can You Crack The Case Of The Crystal Key?|Zach Wissner-Gross (riddlercolumn@gmail.com)|May 28, 2021|FiveThirtyEight
Friend-of-The-Riddler Dean Ballard explored non-isosceles sets in three-dimensional grids.
Can You Crack The Case Of The Crystal Key?|Zach Wissner-Gross (riddlercolumn@gmail.com)|May 28, 2021|FiveThirtyEight
Here are examples of the largest non-isosceles sets for the 5×5 grid and the 6×6 grid, which had seven and nine points, respectively.
Can You Crack The Case Of The Crystal Key?|Zach Wissner-Gross (riddlercolumn@gmail.com)|May 28, 2021|FiveThirtyEight

That meant there were four equilateral triangles plus 18 isosceles triangles, or 22 triangles in total.
Can You Bake The Biggest π?|Zach Wissner-Gross|March 12, 2021|FiveThirtyEight
A gaily coloured hat hung from one of the boats, and over each floated a red flag shaped like an isosceles triangle.
A Woman's Journey through the Philippines|Florence Kimball Russel
Salvage boat take position at apex isosceles triangle 27.6 degrees with lighthouse and summit hill a mile to the south.
Tom Swift and His Giant Telescope|Victor Appleton
A narrow channel running from the Dorsolum to the Abdomen in Coleoptera, forming an isosceles triangle reversed.
An Introduction to Entomology: Vol. III (of 4)|William Kirby
So they crept up to the fire in the formation of an isosceles triangle.
Denis Dent|Ernest W. Hornung
Then ask them if they are equal-legged (isosceles) triangles.
Guide to the Kindergarten and Intermediate Class and Moral Culture of Infancy.|Elizabeth P. Peabody

British Dictionary definitions for isosceles

isosceles

/ (aɪˈsɒsɪˌliːz) /

adjective

(of a triangle) having two sides of equal length

(of a trapezium) having the two nonparallel sides of equal length

Word Origin for isosceles

C16: from Late Latin, from Greek isoskelēs, from iso- + skelos leg

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

Scientific definitions for isosceles

isosceles

[ ī-sŏs′ə-lēz′ ]

Of or relating to a geometric figure having at least two sides of equal length.