Answer:
It is B. (36√5 + 36) ft^2.
Explanation:
Total area = area of the base + 4 * area of the triangular side.
The slant height of a triangular side = √(6^2 + 3^2)
= √45
= 3√5
The area of this side = 3 * 3 √5
= 9√5.
Therefore the total area of the pyramid
= 6^2 + 4*9√5
= (36 + 36√5) ft^2.