Answer:
3 ft^2
Step-by-step explanation:
first find the width of the storage box using the given volume
V = L * W * H
9 = 4 * W * 3
9 = 12 * W
9/12 = W
W = 3/4 or .75
then with that to find the are of the base multiply the length and the width
a = l * w
a = 4 * 3/4
a = 3