[ ahy-sos-uh-leez ]
/ aɪˈsɒs əˌliz /
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(of a straight-sided plane figure) having two sides equal: an isosceles triangle; an isosceles trapezoid.



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“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.

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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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for isosceles

British Dictionary definitions for isosceles

/ (aɪˈsɒsɪˌliːz) /


(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

[ ī-sŏsə-lēz′ ]

Of or relating to a geometric figure having at least two sides of equal length.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.