Geometry and trigonometry
Radian
An angle unit defined by the ratio of arc length to circle radius.
Common notation θ=s/r
In one sentence
What does Radian mean?
An angle unit defined by the ratio of arc length to circle radius.
How it is written
θ=s/r
A compact example
A half-turn is π radians, equal to 180°.
Clear answers
Questions about Radian
What does Radian mean in mathematics?
An angle unit defined by the ratio of arc length to circle radius.
How is Radian written?
A common notation is θ=s/r.
What is an example of Radian?
A half-turn is π radians, equal to 180°.