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

Example Sentences

At their point of contact, a large triangular slice of the addition is cut away, exposing the sides of the boxes and creating a street-level plaza.

From The Wall Street Journal • Mar. 20, 2026

"In principle, this triangular lattice network of properly chosen lanthanide moments can cause a special kind of intrinsically quantum disordered state to arise," Wilson said.

From Science Daily • Mar. 16, 2026

The FAA also cordoned off a triangular zone south of Key West.

From Salon • Jan. 12, 2026

The course began and ended at Palisades Village Green, a small triangular park in the middle of the downtown area.

From Los Angeles Times • Nov. 27, 2025

Anne’s sheik was wearing a black-and-orange-striped blazer, gray Oxford bags, a bow tie on an elastic band, and a brown triangular porkpie hat, pinched into a bowsprit at the front.

From "Cheaper by the Dozen" by Frank B. Gilbreth Jr. and Ernestine Gilbreth Carey

Related Words

• trilateral