Learn All Concepts of Chapter 2 Class 11 Relations and Function - FREE. Check - Trigonometry Class 11 - All Concepts

Let us consider a circle of radius r

Let Angle subtended by whole circle at center be θ

Length of arc = Circumference of circle = 2πr

Now,

We know that

θ = l/r

θ = 2πr/r

θ = 2π

∴ Angle at center of circle in Radians is
**
2
**
**
π
**