Answer:
142 cm²
Explanation:
to find the surface area, you need to find the area of all of the boxes within the image above add them all together.
Starting in the middle row and working from left to right it is,
7×3+7×5+7×3+7×5
21+35+21+35=112
Than the bottom and top box is
3×5+5×3
15+15=30
Than you add both of them together,
112+30=142