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 flatiron building concept was born out of necessity to accommodate triangular road intersections, which came in handy in metropolises such as Indianapolis, New York City and elsewhere. —Powered By, IndyStar, 2 July 2025

The bots on wheels, adorned with triangular eyes that transform to play pong or give heart-eyes to passersby, will deliver up to 10 items within a one mile radius of the store. —Karoline Leonard, Austin American Statesman, 2 July 2025

Launching today, The Sara Dress is a breezy linen midi designed with a triangular bust and finished with a contrasting scalloped-edge trim. —Lauren Alexis Fisher, Footwear News, 25 June 2025

And so our triangular love story progresses over tricky terrain. —Jocelyn Noveck, Boston Herald, 13 June 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

Rhymes for triangular

• quadrangular
• rectangular
• subangular
• angular
• subtriangular

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