# What is *angle*?

**Angle**is a shape formed by two lines or rays diverging from a common point (the vertex).

## Input

**Turn**or

**cycle**, or

**full circle**. is a unit of plane angle measurement equal to 2π radians, 360 degrees or 400 gradians.

## Output

**Radian**is the ratio of the length of a circular arc to the radius of the arc.