Question

how to find out the radius of a circle having he circumference only
eg. circumference= 22 cm

Answer 1

$$\begin{gathered} \mathrm{Circumference}\mathrm{of}\mathrm{circle}=2\mathrm{\pi r} \\ \Rightarrow 22=2\times \frac{22}{7}\times \mathrm{r} \\ \Rightarrow \mathrm{r}=\frac{22\times 7}{2\times 22} \\ \Rightarrow \mathbf{r}\mathbf{=}\mathbf{3}\mathbf{.}\mathbf{5}\mathbf{}\mathbf{cm} \end{gathered}$$