Triangle

The triangle is a percussion instrument, classed as an idiophone in the Hornbostel–Sachs system. It is made of various metals, including aluminium, beryllium copper, brass, bronze, iron and steel, bent into a triangle with one corner left open. It is usually held by a loop of thread or wire at the top corner. In theory it has no definite pitch: struck with a suitable beater, it produces many overtones. It is named after its shape.