Find the surfacs area of a cone wirh a slant height of 18in and a radius of 7in

Formula of the surface area of a cone is:
S.A = Area of base +  × Perimeter of base × height of prism

S.A = r² + rl
       = (7)² + (7)(18)
       = 49 + 126
       = 175 in² (in terms of )
       = 549.7787 in²
       ≈ 550 in²

If your asking how much altogether for 12 performance the answer will be 98,496.