Area of Bottom Rectangle: 12 in X 8 in = 96 in^2
Area of Top Rectangle: 13 in X 8 in = 104 in^2
Area of Side Rectangle: 5 in X 8 in = 40 in^2
Area of Side Triangle: (5 in X 12 in)/2 = (60)/2 = 30 in^2
So total surface area = 96 + 104 + 40 + 2(30) = 300 in^2