Answer:

Explanation:
The formula to calculate the surface area of cuboid with dimensions l by w by h is given by :-

From the given picture, the dimensions of upper block (cuboid) is 5 in. by 5 in. by 8 in.
Then the surface area of the upper block is given by :-

Also, the dimensions of lower block (cuboid) is 10 in. by 10 in. by 2 in.
Then the surface area of the upper block is given by :-

Now, the surface area of design =


Hence, the the surface area of this design =
