Part DSuppose the cylindrical water tank has a radius of 12 feet.


The Solution:
Given that the volume of the cylindrical tank is:
[tex]\begin{gathered} V=\pi\times\text{ square of radius}\times\text{ length of the tank} \\ V=\pi r^2h \end{gathered}[/tex]In this case,
[tex]\begin{gathered} \text{ V=volume of the tank=?} \\ r=\text{ radius=12 ft} \\ h=\text{ length of the tank=20 ft} \end{gathered}[/tex]Substituting these values in the above formula, we get
[tex]V=20\times12^2\times\pi=9047.787\approx9047.8\text{ cubic feet}[/tex]Therefore, the correct answer is approximately 9047.8 cubic feet.