Question
Find the area of a circle whose circurnference is $8\pi.$
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Answer
Let r be the radius of the circle.
Circumference of a circle $=8\pi$
$\Rightarrow2\pi\text{r}=8\pi$
$\Rightarrow\text{r}=\frac82$
$\Rightarrow\text{r}=4$
$\therefore$ Area of a circle $=\pi\text{r}^2=\pi\times4\times4=16\pi$
Circumference of a circle $=8\pi$
$\Rightarrow2\pi\text{r}=8\pi$
$\Rightarrow\text{r}=\frac82$
$\Rightarrow\text{r}=4$
$\therefore$ Area of a circle $=\pi\text{r}^2=\pi\times4\times4=16\pi$
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