what is the perimeter of a sector of a circle whose central angle is 900 and radius is 7 cm? Share with your friends Share 2 Varun.Rawat answered this We have,radius of the sector of circle, r = 7 cmcentral angle, θ = 90°Length of arc = θ360°×2πr = 90°360°× 2×227×7 = 11 cmNow perimeter of sector = r + r + l = 7 + 7 + 11 = 25 cm 2 View Full Answer