Find the perimeter of sector of a circle with radius 6 cm and angle at the centre is 60°.
Soln:- let the length of the sector=l
Given that the radius of circle r =6 cm
And the angle at the centre, θ=60°
We know that ,
angle at the centre=perimeter of sector/the radius of circle
Means, θ=l/r
60°=l/6
l=6×60°
l=6×60°×π/180°3
l=6π/3
l=2π cm
the length of the sector=2π
