Question

Find the diameter of a circle and its circumference if its area is 394.24cmsquare

Answer 1

Dear Student,

$$\begin{gathered} AreaofCircle=394.24c{m}^2 \\ Asweknowthat, \\ AreaofCircle={\mathrm{\pi r}}^2=394.24 \\ \frac{22}{7}\times {\mathrm{r}}^2=394.24 \\ {\mathrm{r}}^2=\frac{394.24\times 7}{22}=125.44 \\ \mathrm{r}=\sqrt{125.44}=11.2\mathrm{cm} \\ d=2r=22.4cm \\ \mathrm{Circumference}=2\mathrm{\pi r}=2\times \frac{22}{7}\times 11.2=70.4\mathrm{cm} \end{gathered}$$

Regards