From Longman Dictionary of Contemporary Englishtriangulartri‧an‧gu‧lar /traɪˈæŋɡjələ $ -ər/ ●○○ adjective 1 CFshaped like a triangle2 COMPETITIONinvolving three people or teams a triangular sporting competition
Examples from the Corpus
triangular• The dorsal arm plates are triangular and nearly contiguous.• On the night stand was a translucent orb atop a triangular clock.• Another looked like a triangular knife at the end of a long stick.• a triangular relationship• Now I saw why, when viewed from the side, the album had such a strange, triangular shape.• The dorsal arm plates are bell shaped or triangular with a convex distal edge and are separated. 