Main Entry: tri·an·gle

Pronunciation: \ˈtrī-ˌaŋ-gəl\

Function: noun

Etymology: Middle English, from Anglo-French, from Latin triangulum, from neuter of triangulus triangular, from tri- + angulus angle

Date: 14th century

1 : a polygon having three sides — compare spherical triangle
2 a : a percussion instrument consisting of a rod of steel bent into the form of a triangle open at one angle and sounded by striking with a small metal rod b : a drafting instrument consisting of a thin flat right-angled triangle of wood or plastic with acute angles of 45 degrees or of 30 degrees and 60 degrees
3 : a situation in which one member of a couple is involved in a love affair with a third person

[triangle illustration]