(geometry) A polygon with three sides and three angles. / (US, Canada) A set square.

plural of triangle

A largely tropical, Old World, erebid moth, Trigonodes hyppasia, with triangular markings on the wings.

The area comprising the cities of Raleigh, Durham and Chapel Hill in North Carolina. Used with "the" except when attributive. / Ellipsis of Bermuda Triangle.

Having three angles. / Located inside a triangle. / (heraldry) Divided into triangles (said of the field).

(geometry) A triangle having each of its three sides of different lengths.

plural of right triangle

A triangle at an intersection, formed by the two roads or rights-of-way and a third line, which must be kept clear of obstructions such as hedges so that people in one road can see cars approaching on the other.

(geometry) A triangle all of the angles of which are acute.

(geometry) A triangle one of whose angles is obtuse.