To find surface area for the rectangular prism, follow the formula:
SA = 2(wl + hl + hw)
Note that:
w = width = 3
l = length = 3
h = height = 6
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Plug in the corresponding numbers into the right variables. Note that you are only looking for the surface area of the larger prism.
SA = 2((3 x 3) + (6 x 3) + (6 x 3))
Simplify. Remember to follow PEMDAS.
SA = 2((9) + (18) + (18))
SA = 2(9 + 18 + 18)
SA = 2(45)
SA = 90
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(B) 90m² is your answer
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hope this helps