Answer:
85 ft^2
Explanation:
Ok, the square base area is 5 x 5 = 25 square feet
the triangular sides have an area of (1/2)(5)(6) each, which is 15 square feet each, like you said.
To find the total surface area, you multiply the 15 square feet x 4 (there are 4 sides) and add the base.
15 x 4 = 60 + 25 = 85 square feet