Question

What is the perimeter of a sector of a circle whose central angle is 90 degree and radius is 7cm ?​

Answer 1

Answer:

25cm

Step-by-step explanation:

given the radius of the sector ,r =  7cm

also, given the central angle = 90°

=> the sector is $\frac{1}{4}$th of a circle

=> the arc length,

(ie. the perimeter of the curved side) = $\frac{1}{4}$th of perimeter of the circle

=> $\frac{1}{4}$ * 2$\pi$r units

= $\frac{1}{4}$*2*$\frac{22}{7}$*7 = 11cm

=> perimeter of the sector =  arc lenght + 2r

                                            = 11 + 2(7) cm

                                            = 11+14 cm

                                            = 25cm