64 cubic feet is the answer you’re lookin for!
Let r be a radius of a given circle and α be an angle, that corresponds to a sector.
The circle area is

and denote the sector area as

.
Then

(the ratio between area is the same as the ratio between coresponding angles).

.
What type of question is this
Sketch the two quadrilaterals and label them as shown in the figure below.
Let x = length of the 4th side of ABCD.
Because ABCD ~ EFGH, therefore
x/5 = 14/6
That is,
x = (5/6)*14 = 11.67 ft
Answer: D. 11.7 ft