$\"\"$

Area of the circle is $\"\"$ .

Observe the figure :

Diameter of the circle $\"\"$ is $\"\"$ .

The radius of the circle is $\"\"$ .

$\"\"$ (Substitute $\"\"$ in the equation)

$\"\"$ (Simplify)

Find area of the circle :

$\"\"$ (Orginal equation)

$\"\"$ (Substitute $\"\"$ in the equation)

$\"\"$ ( $\"\"$ )

Therefore, the area of the circle is $\"\"$ . $\"\"$

The area of the circle is $\"\"$ .