triangular

American  

[trahy-ang-gyuh-ler] / traɪˈæŋ gjə 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

• subtriangularity
  noun
• triangularity
  noun
• subtriangular
  adjective
• 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

See Examples For:

triangular

While removing sheetrock during demolition, workers found remnants of a balcony at the triangular point on the 20th floor, identical to an existing balcony one floor above.

From BBC ● Jul. 26, 2026

The triangular relationship that forms is heartbreakingly brutal yet beautiful, touching something deeper than blood.

From The Wall Street Journal ● Jul. 6, 2026

The fancy vivid blue-green diamond is triangular in shape and "the size of the nail on your smallest finger" according to Fawcett.

From Barron's ● May 13, 2026

You will tape each end of the tail to where it matches the width of the triangular sections to make a connected long loop.

From Los Angeles Times ● May 3, 2026

“St. Martin’s? That’s still standing. It’s in Victory Square, alongside the picture gallery. A building with a kind of a triangular porch and pillars in front, and a big flight of steps.”

From "1984" by George Orwell

Related Words

• trilateral