In higher classes, we don’t use degree to measure angles
We use radians.
We define radian in terms of length of arc:
Angle subtended by an arc of 1 unit in a circle of radius 1 unit is 1 radian.
In other words,
If length of arc is 1 unit
& Radius = 1 unit
Then, angle at center = 1 radian
Note: In θ = l/r i.e. length of arc formula,
Angle is measured in radians
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.