equilateral

[ee-kwuh-lat-er-uhl, ek-wuh-]

adjective

1. having all the sides equal.

   an equilateral triangle.

noun

1. a figure having all its sides equal.

2. a side equivalent, or equal, to others.

equilateral

/ ˌiːkwɪˈlætərəl /

adjective

1. having all sides of equal length

   an equilateral triangle

noun

1. a geometric figure having all its sides of equal length

2. a side that is equal in length to other sides

equilateral

1. Having all sides of equal length, as a triangle that is neither scalene nor isosceles.

Other Word Forms

• equilaterally adverb
• nonequilateral adjective
• nonequilaterally adverb
• subequilateral adjective
• unequilateral adjective
• unequilaterally adverb

Word History and Origins

Origin of equilateral¹

From the Late Latin word aequilaterālis, dating back to 1560–70. See equi-, lateral

Example Sentences

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.

Read more on BBC

These related tilings are made of shapes called polyiamonds, simple tiles formed by combining equilateral triangles.

Read more on Scientific American

She added an equilateral oval line, slightly off-center within the disk’s perfect circle.

Read more on Los Angeles Times

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.

Read more on Washington Post

Some pointed straight and high like an equilateral triangle and others were angled like a sail in the wind.

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Related Words

• rectangular