Given:
Given that the height of the cone is 12 ft.
The volume of the cone is 90 ft³
We need to determine the area of the base of the cone.
Area of the base of the cone:
The area of the base of the cone can be determined using the formula,

where the base area is

Substituting the value of A in the above formula, we get,

Substituting V = 90 and h = 12, we get;


Dividing both sides by 4, we get;

Thus, the area of the base of the cone is 22.5 square feet.
Hence, Option c is the correct answer.