here is the formula for finding the volume of a sphere:
\(\frac43 * \pi * r^3\) (where r is the radius).
so, using that formula, you can plug in r for 3.
\(\frac43 * \pi * 3^3\)
= \(\frac43 * \pi * 27\)
= \(4*\pi*9\) (we can cancel out the 3 in the denominator)
hope this helped! please let me know if you are confused about anything