Answer:
846 sq. in.
Step-by-step explanation:
This is surface area. There are 6 faces. Solve each face and then add them up. In this case, first multiply 9 and 12 = 108. 108 adding 108 because there is another side with the same size. Than multiply 9 and 15. 135 times 2. 216 + 270 = 486. Next you multiply 12 and 15. 180 times 2. 486 + 360 = 846