Answer:
678 ft²
Step-by-step explanation:
The opposite sides of the cuboid are congruent, thus surface area is
2(11 × 9) ← front and back + 2(11 × 12) ← top and base + 2(12 × 9) ← sides
= 2(99) + 2(132) + 2(108)
= 198 + 264 + 216
= 678 ft²
