Question

if the radius of a sphere is tripled, then its surface area increased by ?​

Answer 1

Step-by-step explanation:

Let the radius of the original sphere is r. The Surface area of the new sphere sphere is: 4 π (3r)^2 = 4 π (3)^2 (r)^2 = (3)^2 x 4 π (r)^2 = 9 x 4 π r^2 = 9 times the surface area of the original sphere