The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 12 cm each. The radius of the sphere is:

Question: The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 12 cm each. The radius of the sphere is:

Solution:
Curved surface area of sphere = 4πr₁²
Surface area of cylinder =2πr₂h
diameter = 12 cm
radius r₂ = 6cm

⇒ 4πr₁² = 2πrh
⇒ r₁²= (6 × 12)/2
⇒ r₁² = 36
⇒ r₁ = 6

radius of sphere 6 cm.