12π cm on the Great Circle. The circumference of the great circle =π×9×2= 18π.
The ratio of the intercepted sum to the total number = 12π: 18π = 2: 3.
Therefore, the interception area = 3.14× 9× 9× 2/3 =169.56cm2.
The area of the bottom = 3.14× 6× 6 =113.04cm2.
Cone surface area =169.56+113.04 = 282.6cm2.
I wish you progress in your study!
If you have any questions, please ask them. If you have any understanding, please adopt them in time! (*^__^*)