What is Triangle (disambiguation)?
In [[geometry]], a '''[[triangle (shape)|triangle]]''' is the flat shape formed by joining three points (not in a straight line) with straight line segments. A triangle is a three sided [[polygon]]. In [[music]], a '''[[triangle (instrument)|triangle]]''' is a [[musical instrument]] that is made from a metal tube. It is in the shape of a triangle. It is open at one corner, and when it is hit with a metal stick, it makes a sound. {{disambig}}