a spherical ball is divided into 2 equal halves.if the csa of each half is 56.57cm2,find the volume of the spherical ball

A spherical ball is divided in two equal halves ie. two hemispherical ball.
So suppose r be the radius of spherical ball. This means radius of each hemispherical ball is also r.
CSA of each hemispherical ball = $2{\mathrm{\pi r}}^2 = 56.57 {\mathrm{cm}}^2$
$$\begin{gathered} 2\times \frac{22}{7}{r}^2 = 56.57 \\ \Rightarrow r^2 = \frac{56.57\times 7}{2\times 22} = 8.999\approx 9 \\ \Rightarrow r = \sqrt{9} = 3 \end{gathered}$$
Then volume of spherical ball = $\frac{4}{3}{\mathrm{\pi r}}^3 = \frac{4}{3}\times \frac{22}{7}\times 3^3 = \frac{4}{3}\times \frac{22}{7}\times 27 = 113.142 {\mathrm{cm}}^3$