Assuming that the "9ft" and "11ft" refer to the dimensions of a right circular cone, we can find the surface area of the cone using the formula:
A = πr² + πrl
where r is the radius of the base of the cone, l is the slant height of the cone, and π is approximately equal to 3.14.
To find the radius and slant height, we can use the Pythagorean theorem.
Let's assume that 9ft is the height of the cone, and 11ft is the slant height.
Then, we have:
r² + 9² = 11²
r² + 81 = 121
r² = 40
r ≈ 6.32 ft
Now that we have the radius and slant height, we can find the surface area of the cone:
A = πr² + πrl
A = π(6.32)² + π(6.32)(11)
A ≈ 199.3 square feet
Therefore, the surface area of the cone is approximately 199.3 square feet.