The answer is C, hope this helps!
Hey there :)
We know the volume formula of a triangular prism
Volume = base area × height of prism
We are given:
Base of triangle = 5 ft
Height of triangle = 3 ft
Height of prism = 7.5 ft
Apply the formula
V =

( 5 )( 3 ) × 7.5
= 7.5 × 7.5
= 56.24 ft³
Area of the rectangle minus area of 2 circles
Area of rectangle is 8x16
Area of circle is pi•r^2 = 3.14 x 4^2= 3.14•16
Answer is:
128 - 2(3.14•16) square inches