Mathematics for IGCSE & O level - Mensuration (Section 3 - No. 40)
If the radius of a sphere is halved, how does its surface area change?
It is halved.
It is quartered.
It is doubled.
It is multiplied by 8.
Giải thích
The surface area of the sphere = 4πr². When the radius is halved, the surface area becomes 4π(r/2)² = πr²