Question

If the radius of a sphare is doubled than find the ratio of three areas ?​

Answer 1

 

Let r is the radius of a sphere ,

Then its surface area , $\sf{S_1=4\pi r^2$

If the radius is doubled  ,

Then its surface area , $\sf{S_2=4\pi (2r)^2$ = $\sf{16\pi r^2$

Ratio =  $\displaystyle\sf{\frac{S_2}{S_1}=\frac{16\pi r^2}{4\pi r^2}=\frac{4}{1}=4:1$

$\boxed{\displaystyle\sf{Ratio=4:1}}$