The circumference of a circular field is 308 m. Find its :

(i) radius

(ii) area.

(i) Let r be the radius of the circle.

The circumference of a circle = 308 m

As we know, the circumference of a circle = 2πr

$⇒ 2 \times \dfrac{22}{7} \times r = 308\\[1em] ⇒ \dfrac{44}{7} \times r = 308\\[1em] ⇒ r = \dfrac{308 \times 7}{44}\\[1em] ⇒ r = \dfrac{2,156}{44}\\[1em] ⇒ r = 49 \text{ m}^2$

Hence, the radius of a circle is 49 m.

(ii) Area of a circle = πr²

$= \dfrac{22}{7} \times 49^2\\[1em] = \dfrac{22}{7} \times 2,401\\[1em] = \dfrac{52,822}{7}\\[1em] = 7,546 \text{ m}^2$

Hence, the area of a circle is 7,546 m².