We are asked to solve for the surface area of the described figure in the problem. We can conclude that the given figure is a rectangular prism since it was being mentioned in the problem that the height is laid flat. Therefore, the formula for the surface area is SA = PH + 2B where "P" stands for the perimeter of the rectangle and "B" stands for the area of the rectangle while "H" is for the height.
Solving for P, we have it:
P = width + length + width + length
P = 10 + 5 + 10 + 5
P = 30 inches
Solving for B, we have it:
B = length * width
B = 10 * 5
B = 50 inches squared
Solving for the surface area, we have it:
SA = PH + 2B
SA = 30*7 + (2*50)
SA = 310 inches squared
The answer is 310 in2.
