Question

Question 12

The circumference of a circle is 31.4 cm. Find the radius and the area of the circle.
$(Take\pi =3.14)$

Answer 1

The circumference of the circle = 31.4 cm
We know that, circumference of a circle = $2\pi r$
$\Rightarrow$ $2\pi r=31.4$
$\Rightarrow$ $2\times 3.14\times r=31.4$
$\Rightarrow$ $r=\frac{31.4}{2\times 3.14}=5cm$
The area of the circle = $\pi r^2$
$=3.14\times 5\times 5$
$=78.5c{m}^2$
Therefore, the radius and the area of the circle are 5 cm and 78.5 $c{m}^2$ respectively.