A triangular prism has a surface area of 475 square feet, a length of 15 feet, a height of 10 feet, and sides of 5 feet. Find the width of the base of the triangular prism

Total surface area of a triangular prism = width x height + (sum of sides + width) x length

475 = (width x 10) + (5 + 5 + width) x 15

475 = (10 x width) + (10 + width) x 15

475 = (10 x width) + 150 + (15 x width)

475 - 150 = 25 x width

325 = 25 x width

width = 325/25 = 13 feet