triangular

American  

[trahy-ang-gyuh-ler] / traɪˈæŋ gyə lər /

adjective

1. pertaining to or having the form of a triangle; three-cornered.

2. having a triangle as base or cross section.

   a triangular prism.

3. comprising three parts or elements; triple.

4. pertaining to or involving a group of three, as three persons, parties, or things.

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triangular British  

/ traɪˌæŋɡjʊˈlærɪtɪ, traɪˈæŋɡjʊlə /

adjective

1. Also: trigonal.  of, shaped like, or relating to a triangle; having three corners or sides

2. of or involving three participants, pieces, or units

3. maths having a base shaped like a triangle

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Other Word Forms

• subtriangular adjective
• subtriangularity noun
• triangularity noun
• triangularly adverb

Etymology

Origin of triangular

1535–45; < Latin triangulāris, equivalent to triangul ( um ) triangle + -āris -ar ¹

Explanation

Anything that looks like a a shape with three sides and three angles is triangular. If you see a triangular fin in the ocean while you’re swimming, watch out! Shark! Start looking for triangular shapes and you'll begin to see them everywhere, from a triangular slice of pizza to a tortilla chip. Like triangle, triangular is rooted in the Latin tri-, "three," and angulus, "angle or corner." You'll also occasionally find this adjective describing things that involve three people, like a triangular relationship between three best friends.

Example Sentences

They are part of HS2's Delta junction, a complex triangular network of 13 viaducts, and will allow southbound trains to join the spur into Birmingham Curzon Street and the rolling stock depot at Washwood Heath.

From BBC • Apr. 16, 2026

Their study, titled "Interleaved bond frustration in a triangular lattice antiferromagnet," examines how multiple forms of frustration can arise in these systems.

From Science Daily • Mar. 16, 2026

They were spared the unease of the Cabo San Lucas couples retreat and sent to Malibu instead due to budgetary restrictions and their lack of triangular tension.

From Salon • Mar. 8, 2026

O’Neill resolves the triangular conflict with a combination of religious fervor, metaphoric brooding and scabrous humor.

From Los Angeles Times • Dec. 15, 2025

Its pale light cast the shadows of the tall triangular merlons across the frozen ground, a line of sharp black teeth.

From "A Dance with Dragons" by George R. R. Martin

Related Words

• trilateral