Given:
A circle with diameter 9 cm.
To find:
The area of the circle.
Solution:
The area of a circle is:
...(i)
Where r is the radius.
We know that, the diameter of a circle is twice than its radius.
The diameter of the given circle is 9 cm.
Substituting in (i), we get
Therefore, the area of the given circle is 63.6.