Answer: The surface area of the planter will be 120.5 square feet.
Step-by-step explanation: in our shape, we will have 5 sides. The base and the four sides going up from each edge of the base.
The base will be 7 x 5 = 35 square feet.
The front and back side will each be 7 x 0.75 = 5.25 square feet.
The left and right side will each be 5 x 0.75 = 3.75 square feet.
If we add up the 5 faces we get:
35 + 5.25 + 5.25 + 3.75 + 3.75 = 120.5 square feet