isosceles
Americanadjective
adjective
-
(of a triangle) having two sides of equal length
-
(of a trapezium) having the two nonparallel sides of equal length
Etymology
Origin of isosceles
1545–55; < Late Latin < Greek isoskelḗs with equal legs, equivalent to iso- iso- + skél ( os ) leg + -ēs adj. suffix
Explanation
In geometry, the word isosceles describes a triangle with two sides that are the exact same length. The angles across from each equal side are also the same in an isosceles triangle. Mathematicians use the term isosceles in two slightly different ways. The Greek mathematician Euclid defined an isosceles triangle as having exactly (and only) two equal sides. Modern geometry experts tend to say that a triangle is isosceles if at least two sides are equal — making an equilateral triangle (with three equal sides) also an isosceles triangle. The Greek root, isoskeles, means "with equal legs."
Vocabulary lists containing isosceles
The ACT Math Test: Geometry, List 1
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National Spelling Bee '14: Prelims Round 3
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Geometry - Introductory
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The server stops by to shout about whether I’m enjoying my wine, a glass of Justin Isosceles, a red blend from California that she’s recommended to go with the filet.
From Seattle Times • Jun. 24, 2022
DISCIPLE: I just ran into Isosceles and he has a great idea for a new triangle.
From New York Times • Jan. 31, 2018
Roosevelt particularly scorned Duchamp's Nude Descending a Staircase, and wondered if the painter belonged to the school of "Parallelopipedonists, or Knights of the Isosceles Triangle".
From The Guardian • Mar. 17, 2013
Cosine and Isosceles were in college by the time JT’s brother, Red, finally pulled up to the curb.
From "The Lions of Little Rock" by Kristin Levine
I was too busy thinking about Cosine and his little sister, Isosceles.
From "The Lions of Little Rock" by Kristin Levine
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
