Question

Find the area of the circle whose circumference is $110cm.$

Answer 1

We want to find out the area of a circle$.$

It is given that circumference of the circle $=110cm$

we know that circumference of the circle $=2\mathrm{\pi r}$

Where $r$ is the radius of the circle$.$

$2\mathrm{\pi r}=110$

$2\times \frac{22}{7}\times r=110$

$r=\frac{110\times 7}{44}$

$r=\frac{10\times 7}{4}$

$r=\frac{70}{4}$

$r=17.5$

Area of the circle $=\mathrm{\pi }{\mathrm{r}}^2$

$=\frac{22}{7}\times \frac{70}{4}\times \frac{70}{4}$

$=\frac{22\times 10\times 70}{4\times 4}$

$=\frac{11\times 5\times 70}{4}$

$=11\times 5\times 17.5$

$=962.5c{m}^2$

Hence, the area of a circle is $962.5c{m}^2$