Answer:
277.2 in²
Step-by-step explanation:
The surface area consists of 3 rectangles of the sides, and the two base triangles.
The front rectangle has dimensions of 12x9, so it's area is 108 in²
The back rectangle has dimensions of 7x9, so it's are is 63 in²
The side rectangle has dimensions of 7x9, so it's area is 63 in²
The top and bottom triangles have a base of 12 and a height of 3.6, so their area is
A = (1/2)(12)(3.6) = 43.2/2, but there are 2 of them, so their combined area is (43.2/2)(2) = 43.2 in²
The total surface area is 108 + 63 + 63 + 43.2 = 277.2 in²
