The diameter of a circle is 12 cm. Find its area.

Concept: The area of a circle is the region of a two-dimensional plane occupied by the circle. It is simple to calculate using the formula  $A={\mathrm{\pi r}}^2$.

Here, diameter =12 cm

Now, 

$r=\frac{12}{2}=6 cm$

Then, the area is, $A={\mathrm{\pi r}}^2$

$\Rightarrow A=\mathrm{\pi }\times 6^2$

$\Rightarrow A=36\mathrm{\pi } {\mathrm{cm}}^2$

Hence, the area of given circle is $36\mathrm{\pi } {\mathrm{cm}}^2$