Answer:
Area,
![A=(81\pi )\ cm^2](https://img.qammunity.org/2019/formulas/mathematics/college/3hjcczt1k1rpj1xcgmhqeobt18o4z9tf2i.png)
Explanation:
Given that,
The diameter of the circle, d = 18 cm
The radius of a circle is half of its diameter, r = 9 cm
The formula to find the area of a circle is given by :
![A=\pi r^2](https://img.qammunity.org/2019/formulas/mathematics/college/9r1re7h0vhetpbxpblka8qcs1byr9oap9f.png)
When r = 9 cm
![A=\pi (9\ cm)^2](https://img.qammunity.org/2019/formulas/mathematics/college/mk1l2a0nlwa5so3egczkxggevo473is1ke.png)
![A=(81\pi )\ cm^2](https://img.qammunity.org/2019/formulas/mathematics/college/3hjcczt1k1rpj1xcgmhqeobt18o4z9tf2i.png)
So, the area of the circle is
. Hence, this is the required solution.