H=2ft
d=6 ft
r=d/2
r=6/2=3ft
V= π•r^2•h
V=3.14•3^2•2
V=3.14•9•2
V=56.52 ft3
V~56.5ft3

So the answer is choice D. You can check this by differentiating the right hand side and you'll get x^3 back again.
This answer can be found by using the power rule for integrals. That rule is
Answer:
The total volume of the whole figure is 576m³.
Step-by-step explanation:
First find the volume for the first figure.
Volume of a Rectangular Prism (formula): L•W•H
V = (15m)(12m)(2m)
V = 360m³
Now, find the volume for the second figure.
V = (6m)(12m)(3m)
V = 216m³
Finally, just add both volumes to find the total volume of the entire figure.
Vt = 216m³ + 360m³
Vt = 576m³