Question

Find the circumference and area of the circle if radius is $2.1m$

Answer 1

Step 1 Finding the circumference of the circle:

Circumference of the circle=$2\mathrm{\pi r}\mathrm{where}\mathrm{r}\mathrm{is}\mathrm{the}\mathrm{radius}\mathrm{of}\mathrm{the}\mathrm{circle}.$

$$\begin{gathered} =2\times \frac{22}{7}\times 2.1 \\ =2\times 22\times 0.3 \\ =13.2m. \end{gathered}$$

Hence, the circumference of the circle is $13.2m.$

Step 2 Finding the area of the circle:

Area of the circle=${\mathrm{\pi r}}^2\mathrm{where}\mathrm{r}\mathrm{is}\mathrm{the}\mathrm{radius}\mathrm{of}\mathrm{the}\mathrm{circle}.$

$$\begin{gathered} =\frac{22}{7}\times 2.1\times 2.1 \\ =22\times 0.3\times 2.1 \\ =13.86m^2. \end{gathered}$$

Hence, the area of the circle is $13.86m^2.$