Listen NCERT Audio Books - *Kitabein Ab Bolengi*

2

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’ = πd^{2}

(i) d is 14 cm

⇒ surface area = (22/7) × (14)^{2} = 616 cm^{2}

(ii) d is 21 cm

⇒ surface area = (22/7) × (21)^{2} = 1386 cm^{2}

(iii) d is 3.5 cm

⇒ surface area = (22/7) × (3.5)^{2} = 38.5cm^{2}