A student found the surface area of this pyramid. Surface area = (12)(6) + 1 2 (12)(8) + 1 2 (6)(9.5) = 72 + 48 + 28.5 = 148.5cm² What error did the student make? The student should have used the same value for all of the triangular faces. The student added only three of the five faces. The student did not use the correct formula to find the area of the triangular faces. The student did not find the correct area of the rectangular base.