triangular

adjective

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

1

a

: of, relating to, or having the form of a triangle

a triangular plot of land

b

: having a triangular base or principal surface

a triangular table

a triangular pyramid

2

a(1)

: of, relating to, or involving three elements

a triangular agreement

(2)

of a military group : based primarily on three units

b

: of or relating to a love triangle

triangularity

(ˌ)trī-ˌaŋ-gyə-ˈler-ə-tē 

-ˈla-rə-tē

noun

triangularly

trī-ˈaŋ-gyə-lər-lē 

adverb

Examples of triangular in a Sentence

Recent Examples on the Web

The flipper-edge skin, however, was made up of small triangular structures similar to modern-day reptile scales. —Ben Coxworth, New Atlas, 7 Feb. 2025

At the hip, belt, and shoulder strap were triangular, gold buckle details. —Kathleen Walsh, Glamour, 3 Feb. 2025

At the top of the skyscraper is the Edge, the tallest outdoor observation deck in the Western Hemisphere, a triangular patio jutting over the metropolis. —Justin Nobel, Harper's Magazine, 2 Jan. 2025

Stag Stool Bois De Marais is a triangular bog-wood chair with a spiky moose antler as its back support. —Osman Can Yerebakan, Curbed, 13 Jan. 2025

Word History

Etymology

Middle English trianguler, from Late Latin triangularis, from Latin triangulum

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing triangular

• triangular number

Kids Definition

triangular

adjective

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

1

: of, relating to, or having the form of a triangle

2

: having a triangular base or principal surface

a triangular pyramid

Medical Definition

triangular

noun

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

: triquetral bone