Question

The circumference of a circle is 22 cm.

Answer 1

$\bf \: Circumference \: of \: a \: circle = 2\pi \: r$

$\implies22 = 2 \times \dfrac{22}{7} r$

$\implies22 = \dfrac{44}{7} \times r$

$\implies \: r = \dfrac{22 \times 7}{44}$

$\implies \boxed{ r = \dfrac{7}{2} }$

Now,

$\bf \: Area \: of \: circle = \pi {r}^{2}$

$\rightarrow \: \frac{22}{7} \times ({ \frac{7}{2}) }^{2}$

$\rightarrow \frac{22}{ \cancel7} \times \frac{ \cancel{49}}{4}$

$\rightarrow \: 22 \times \frac{7}{4}$

$\rightarrow \: 11 \times \frac{7}{2}$

$\rightarrow \frac{77}{2}$

$\rightarrow \: 38.5 \: cm {}^{2}$

Area of rectangle = 38.5 cm².