Answer:
117 ft²
Step-by-step explanation:
Surface area of triangular pyramid = base area + ½(Perimeter of base * slant height)
Base area = ½*b*h = ½*9*6 = 27 ft²
Slant height = √(6² + 4.5²) = 7.5 ft (pythagorean theorem)
Perimeter = 7.5 + 7.5 + 9 = 24 ft
Plug in the values into the formula for surface area
Surface area = 27 + ½(24 * 7.5) = 117 ft²
