The surface area of the given figure is the sum of the area of the six faces.
Two of them have an area A1:
A1 = 2.5 x 4 ft² = 10 ft²
Other two have an area A2:
A2 = 1.25 x 2.5 ft² = 3.125 ft²
and the other two have an area A3:
A3 = 1.25 x 4 ft² = 5 ft²
Then, the total surface area is:
AT = 2(A1) + 2(A2) + 2(A3)
AT = 2(10 ft²) + 2(3.125 ft²) + 2(5 ft²)
AT = 36.25 ft²
Hence, the total surface area of the given figure is 36.25 ft²