isos·​ce·​les | \ ī-ˈsäs-ˌlēz How to pronounce isosceles (audio) , -ˈsä-sə- \

Definition of isosceles

1 of a triangle : having two equal sides — see triangle illustration
2 of a trapezoid : having the two nonparallel sides equal

Examples of isosceles in a Sentence

Recent Examples on the Web Geographically, Richland, Hammonton, and Absecon don't form an isosceles triangle. Phil Anastasia,, "St. Augustine's new head coach will continue non-public rivalry," 26 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'isosceles.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of isosceles

1551, in the meaning defined at sense 1

History and Etymology for isosceles

Late Latin isosceles having two equal sides, from Greek isoskelēs, from is- + skelos leg; perhaps akin to Old English sceol wry

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The first known use of isosceles was in 1551

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Cite this Entry

“Isosceles.” Dictionary, Merriam-Webster, Accessed 6 Aug. 2020.

More from Merriam-Webster on isosceles

Spanish Central: Translation of isosceles

Nglish: Translation of isosceles for Spanish Speakers

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