Answer:
126 in^2
Explanation:
The surface area can be found from the surface area formula:
SA = 2(LW +LH +WH)
I like to rearrange it slightly to ...
SA = 2(LW +H(L +W))
For the given dimensions, the area is ...
SA = 2(6·3 + 5(6 +3)) = 2(18 +45) = 126 . . . . square inches