isosceles

[ahy-sos-uh-leez]

adjective

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

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. 2019

Examples from the Web for isosceles

Historical Examples of isosceles

In an isosceles triangle the angles opposite the equal sides are equal.
The Teaching of Geometry
David Eugene Smith
And equilaterals, and isosceles triangles, and all that, scoffed Neale.
The Corner House Girls on a Tour
Grace Brooks Hill
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
That the angles at the base of an isosceles triangle are equal.
A History of Science, Volume 1(of 5)
Henry Smith Williams

British Dictionary definitions for isosceles

isosceles

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

Word Origin and History for isosceles

adj.

"having two equal sides," 1550s, from Late Latin isosceles, from Greek isoskeles "with equal sides," from isos "equal" (see iso-) + skelos "leg" (see scalene).

isosceles in Science

isosceles

[ī-sŏs′ə-lēz′]

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