equilateral
Americanadjective
noun
-
a figure having all its sides equal.
-
a side equivalent, or equal, to others.
adjective
noun
-
a geometric figure having all its sides of equal length
-
a side that is equal in length to other sides
Other Word Forms
- equilaterally adverb
- nonequilateral adjective
- nonequilaterally adverb
- subequilateral adjective
- unequilateral adjective
- unequilaterally adverb
Etymology
Origin of equilateral
From the Late Latin word aequilaterālis, dating back to 1560–70. See equi-, lateral
Explanation
A shape is equilateral if all the sides are the same length. In geometry class, people learn about many shapes, such as triangles and squares. A square is equilateral, because all of its sides are the same length. A rhombus is also equilateral — its sides are also the same length. A triangle can be equilateral too, but not a scalene triangle, which has three sides of different lengths. The word equal should help you remember what equilateral means. You can also use it as a noun for an equilateral shape.
Vocabulary lists containing equilateral
STAAR Grade 5 Mathematics: Geometry — Triangles, Polygons, and Prisms
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STAAR Grade 8 Mathematics: Geometry and Measurement, List 2
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Geometry, List 2
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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.
Lisa will use the same principle but fire its beams over a much greater distance, and between three identical spacecraft arranged as an equilateral triangle.
From BBC • Jan. 25, 2024
Often, the sandbox game is about the quiet joys of pastoral life, where players construct homesteads, rear livestock, and grow crops in a world made up entirely of perfectly equilateral cubes.
From Slate • Mar. 24, 2023
She added an equilateral oval line, slightly off-center within the disk’s perfect circle.
From Los Angeles Times • Jan. 6, 2023
The equilateral cross with its legs bent at right angles is a millennia-old sacred symbol in Hinduism, Buddhism and Jainism that represents peace and good fortune.
From Washington Post • Dec. 2, 2022
Some pointed straight and high like an equilateral triangle and others were angled like a sail in the wind.
From "The Line Tender" by Kate Allen
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.
