Find the surface areas and volumes of spheres of the following radii.

i. 4 cm ii. 9 cm

iii. 3.5 cm. (π = 3.14)

(i). When radius (r) = 4 cm

Surface area of the sphere is given by,

Surface area = 4πr²

⇒ Surface area = 4 × 3.14 × 4²

⇒ Surface area = 200.96

Volume of the sphere is given by,

Volume =

⇒ Volume =

⇒ Volume = 267.95

Thus, surface area of sphere is 200.96 cm² and volume of sphere is 267.95 cm³.

(ii). When radius (r) = 9 cm

Surface area of the sphere is given by,

Surface area = 4πr²

⇒ Surface area = 4 × 3.14 × 9²

⇒ Surface area = 1017.36

Volume of the sphere is given by,

Volume =

⇒ Volume =

⇒ Volume = 3052.08

Thus, surface area of sphere is 1018.29 cm² and volume of sphere is 3052.08 cm³.

(iii). When radius (r) = 3.5 cm

Surface area of the sphere is given by,

Surface area = 4πr²

⇒ Surface area = 4 × 3.14 × 3.5²

⇒ Surface area = 153.86

Volume of the sphere is given by,

Volume =

⇒ Volume =

⇒ Volume = 179.50

Thus, surface area of sphere is 153.86 cm² and volume of sphere is 179.50 cm³.