Answer:
The volume of a cone is given by the formula V = 1/3πr²h, where r is the radius of the circular base and h is the height of the cone.
Since the diameter of the circular base is 18 inches, the radius is 9 inches. The height of the cone is 3 inches.
Substituting the values in the formula, we get:
V = 1/3π(9²)(3) V = 81π/3 V = 27π
Therefore, the exact volume of the cone is 27π cubic inches.