ANSWER: 288 sq inches.
EXPLANATION: Start by making your 6x4x12 prism. Then, take each side piece by piece. 6x12 for the front and back side, 12x4 for the left and right sides, and 6x4 for the top and bottom. Add those 6 answers together, (72+72+48+48+24+24) and you get 288. Im guessing this is sq inches so 288sq inches.