Answer:
1476 cm²
Step-by-step explanation:
I like to use the formula ...
SA = 2(LW +H(L +W))
= 2((12 cm)(9 cm) + (30 cm)(12 cm +9 cm))
= 2(108 cm² +(30 cm)(21 cm))
= 2(108 cm² +630 cm²) = 2(738 cm²)
total surface area = 1476 cm²
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"Lateral surface area" usually refers to the area that is not part of the base(s). For a rectangular prism, it would be the product of the height and the perimeter of the base. You have not designated a base, so we cannot tell if you really want just the lateral surface area or the whole surface area. The above computation figures the whole surface area.
