Question

Find the perimeter of s sector of a circle whose central angle is 90°and radius is 7cm

Answer 1

Here θ = 90 degree

r = 7 cm

 Length of-arc = (θ/360) x 2Πr

                                =  (90/360) x 2 x (22/7) x 7

                                =  (1/4) x 2 x 22

                                =   (1/2) x 22

                                =   11 cm

Answer 2

Given: Central angle of a circle = 90° And radius of circle is 7 cm

To find: To find the perimeter of sector of a circle

Step-by-step explanation:

As we know

Circumference of sector is given by

 $C=2\pi r \dfrac{\theta}{360^\circ}$ where C is circumference, r is radius , ∅ is the central angle

So we have

$C= 2\times \pi \times 7 \times \dfrac{90^\circ }{360^\circ} = 2\times \dfrac{22}{7} \times 7\times \dfrac{1}{4} = 11cm$

Hence, perimeter of a circle with radius 7 cm and central angle  90°  is 11 cm