Question
Find the area of a circle whose circumference is 44cm.
✓
Answer
Circumference of a circle = 44cmLet r be the radius,
then $2\pi\text{r}=\text{circumference}$
$\Rightarrow2\times\frac{22}{7}\text{r}=44\Rightarrow\text{r}=\frac{44\times7}{2\times22}=7$
$\therefore$ Area of the circle $=\pi\text{r}^2=\frac{22}{7}(7)^2\text{cm}^2$
$=\frac{22}{7}\times7\times7=154\text{cm}^2$
then $2\pi\text{r}=\text{circumference}$
$\Rightarrow2\times\frac{22}{7}\text{r}=44\Rightarrow\text{r}=\frac{44\times7}{2\times22}=7$
$\therefore$ Area of the circle $=\pi\text{r}^2=\frac{22}{7}(7)^2\text{cm}^2$
$=\frac{22}{7}\times7\times7=154\text{cm}^2$
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