Answer:
The answer is B.
Explanation:
It is given that the formule of volume of prism is V = a × h where a stands for area of cross-section. Then, substitute the following value into the formula :
V = 864 in³
h = 18 in
a = ?
864 = a × 18
Next, you have to make a as the subject by dividing 18 on both sides :
864 ÷ 18 = a × 18 ÷ 18
48 = a
a = 48 in²