Question

Find the area of a quadrant of a circle whose circumference is 20 cm.​​

Answer 1

$\huge\red{ Question}$

Find the area of a quadrant of a circle whose circumference is 20 cm.

$\huge\blue{Answer}$

Given, circumference of a quadrant = 20

$\rightarrow \: \frac{2\pi \: r}{4} \: = \: 20 \:$

$\rightarrow \: \pi \: r = \: 40$

$\rightarrow \: r \: = \frac{40}{\pi}$

Now, area of quadrant =

$\frac{\pi {r}^{2} }{4}$

$= \frac{\pi}{4} \times ( \frac{40}{\pi} {)}^{2}$

$= \frac{\pi}{4} \times \frac{1600}{ {\pi}^{2} } \: = \frac{400}{22/7}$

$\frac{=1400}{11}$

$\boxed{= 127.27 \: {cm}^{2} }$