9514 1404 393
Answer:
240 m²
Explanation:
The lateral surface area is given by the formula ...
LA = πrs . . . . . cone with radius r and slant height s
The base area is given by the formula ...
BA = πr²
The total surface area is the sum of these:
SA = BA +LA = πr² +πrs = πr(r+s)
The radius is half the diameter, so is 9m/2 = 4.5 m. Then the surface area is ...
SA = π(4.5 m)(4.5 m +12.5 m) = 76.5π m² ≈ 240 m²