A plane figure bounded by three straight lines and having three angles.

(几何)三角形。

A musical instrument consisting of a steel rod bent in the form of a triangle, sounded by being struck by a metallic rod.

【乐】三角铁。

Any triangular object.

三角形的东西。

Situation in which two persons are both in love with a third person.

(恋爱之)三角关系。