Find the surface area of a sphere of diameter :
(i) 14 cm
(ii) 21 cm
(iii) 3.5 cm
Surface area of a sphere of diameter ‘d’ = πd2
(i) d is 14 cm
⇒ surface area = (22/7) × (14)2 = 616 cm2
(ii) d is 21 cm
⇒ surface area = (22/7) × (21)2 = 1386 cm2
(iii) d is 3.5 cm
⇒ surface area = (22/7) × (3.5)2 = 38.5cm2