Adjective

(en adjective)

Shaped like a triangle.

* {{quote-book, year=1963, author=(Margery Allingham)

, title=(The China Governess) , chapter=Foreword citation , passage=A very neat old woman, still in her good outdoor coat and best beehive hat, was sitting at a polished mahogany table on whose surface there were several scored scratches so deep that a triangular piece of the veneer had come cleanly away, […].}}

Of, or pertaining to, triangles.

Having a triangle as a base; as, a triangular prism, a triangular pyramid.

Having three elements or parties; trilateral, tripartite.