Surface area of the 2 triangle = 2(1/2 x 4.5 x 6) = 327 in²
Surface area of the 3 side rectangles = (4.5 + 7.5 + 6) x 12
Surface area of the 3 side rectangles = 18 x 12
Surface area of the 3 side rectangles = 216 in²
Total surface area = 27 + 216 = 243 in²
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Answer: Surface area = 243 in²
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