There are three possible ways to cut the prism by a plane parallel to a face.First:Therefore, through the creation of the two new prisms there would be two faces added each having a surface area of 2×4=8 increasing the total surface area by 16ft2.Second:Therefore, through the creation of the two new prisms there would be two faces added each having a surface area of 7×4=28 increasing the total surface area by 56ft2.Third:Therefore, through the creation of the two new prisms, there would be two faces added each having a surface area of 7×2=14 increasing the total surface area by 28ft2.Therefore, the maximum increase in surface area would be 56ft2.