1. **State the problem:** We need to find the area of a circle given its diameter is 18 inches. 2. **Formula:** The area $A$ of a circle is given by the formula $$A = \pi r^2$$ where $r$ is the radius of the circle. 3. **Find the radius:** The radius $r$ is half the diameter, so $$r = \frac{18}{2} = 9$$ inches. 4. **Calculate the area:** Substitute $r = 9$ into the area formula: $$A = \pi \times 9^2 = \pi \times 81 = 81\pi$$ 5. **Final answer:** The area of the circle is $$81\pi$$ square inches.