The circumference of a circle is 31.4 cm. Find the radius.

Given,

The circumference of the circle = 31.4 cm.

The circumference of the circle = $2\mathrm{\pi }\times \mathrm{radius}$.

 $31.4 = 2\times 3.14\times \mathrm{radius}$  (we know that $\mathrm{\pi }=3.14$)

$\mathrm{radius}=\frac{31.4}{2\times 3.14}= 5\mathrm{cm}$

Therefore, the radius of the circle is 5 cm.