Answer: 1656 cm²
Explanation:
Rectangular prism is like the shape of a box
Surface Area = LA + 2B Are is what you are looking for cover box
LA = Ph P, Perimeter=30+30+6+6 = 72 h=18
LA= (72)(18)
=1296
B= Lw= (30)(6) = 180
SA = LA + 2B
= 1296 + 2(180)
=1656 cm²