Find the area of a circle, whose diameter is 126 cm.

$\Rightarrow \mathrm{radius}=\frac{\mathrm{diameter}}{2}$

$\Rightarrow \mathrm{r}=\frac{126}{2}$

Area of circle $= {\mathrm{\pi r}}^2$

$\begin{array}{c}= \frac{22}{7} \times \frac{126 }{2}\times \frac{126 }{2} \\ = \frac{ (22 \times 126\times 126 )}{7\times 2\times 2}\\ =12474 {\mathrm{cm}}^2\end{array}$