The bottom is a square with a side length of 2 ft.
The area of a square is Area = S^2 = 2^2 = 4 square ft. Bottom)
The area of one side ( triangle) = 1/2 x base x height = 1/2 x 2 x 4 = 4 square ft.
There are 4 triangles: 4 x 4 sq. ft. = 16 sq.ft. ( four sides)
Total area = four sides + bottom = 16 + 4 = 20 feet^2