The lid will have a base area of 55 1/4 square inches. The long sides of the lid will each have an area of 17 square inches. The short sides of the lid will each have an area of 13 square inches. The total surface area of the lid will be 115 1/4 square inches.
So, for the base, you have w = 6.5 and l = 8.5. Area = 6.5 * 8.5 = 55.25 = 55 1/4.
For the long sides, you have l = 8.5 and h = 2. Area = 8.5 * 2 = 17
For the short sides, you have w = 6.5 and h = 2. Area = 6.5 * 2 = 13
For the total surface area, you have one base which is 55.25, you have two long sides which are 2 * 17 = 34, and you have two short sides which are 2 * 13 = 26. 55.25 + 34 + 26 = 115.25 = 115 1/4.
