Question

If the area of the circular tin plate is $38.5c{m}^2$ then, its circumference is?

Answer 1

Area of the circular plate $=38.5c{m}^2$

$\therefore \pi r^2=38.5$ where $r$ is the radius of the circular plate.

$\Rightarrow r^2\times \frac{22}{7}=38.5$

$\Rightarrow r^2=38.5\times \frac{7}{22}$

$\Rightarrow r^2=12.25$

$\therefore r=3.5cm$

Hence, circumference of the plate $=2\pi r$

$=2\times \frac{22}{7}\times 3.5$

$=22cm$

Hence, circumference of the plate is $22cm$.