The surface area of a sphere is \(A = 4 \pi r^{2}\) and if the original S.A was is enlarged to have it 9 times greater, the radius would be multiplied by 3 or roughly 2.99626 rounded off to 3.0.
For example, let us assign values.
Let A=90
A= 90*9 = 810
\(90 = 4 \pi r^{2}\) and \(810 = 4 \pi r ^{2}\)
the first r is 2.68 and the second r is 8.03
then, \(\frac{8.03}{2.68} = 2.99626\) or rounded off to 3.
