1 foot = 12 inches
(1 foot)³ = (12 inches)³
12³ = 1,728 in³
To change 10 cubic feet into cubic inches
10 ft³ x 1728 in³/ft³ = 17,280 in³
So the answer will be:
C. Multiply by 1,728
Rational due to it’s a multiple

Then

which is a disk of radius 1, hence with area
.
If it is perimeter do this L+W×2
If it's area do this L×W