Question

Radii of the circles are given below, find their areas. 

i. 28 cm 

ii. 10.5 cm 

iii. 17.5 cm

Answer 1

i. Radius of the circle (r) = 28 cm … [Given] 

Area of the circle = πr² 

= (22/7) x (28)² 

= (22/7) x 28 x 28 

= 22 x 4 x 28 

= 2464 sq. cm

ii. Radius of the circle (r) = 10.5 cm … [Given] 

Area of the circle = πr² 

= (22/7) x (10.5)² 

= (22/7) x 10.5 x 10.5 

= 22 x 1.5 x 10.5 

= 346.5 sq. cm

iii. Radius of the circle (r) = 17.5 cm … [Given] 

Area of the circle = πr² 

= (22/7) x (17.5)² 

= (22/7) x 17.5 x 17.5 

= 22 x 2.5 x 17.5 

= 962.5 sq. cm