Question

The radii of some circles are given below. Find their areas.

(1) 28 cm
(2) 5.6 m
(3) 7.7 m
(4) 6.3 m
(5) 35 cm

Answer 1

(1) Radius of the circle is 28 cm.
Area = πr²
= π × 28 cm × 28 cm
= 2464 sq cm $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
∴ Area of the circle is 2464 sq cm.

(2) Radius of the circle is 5.6 m.
Area = πr²
= π × 5.6 m × 5.6 m
= 98.56 sq m $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
∴ Area of the circle is 98.56 sq m.

(3) Radius of the circle is 7.7 m.
Area = πr²
= π × 7.7 m × 7.7 m
= 186.34 sq m $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
∴ Area of the circle is 186.34 sq m.

(4) Radius of the circle is 6.3 m.
Area = πr²
= π × 6.3 m × 6.3 m
= 124.74 sq m $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
∴ Area of the circle is 124.74 sq m.

(5) Radius of the circle is 35 cm.
Area = πr²
= π × 35 cm × 35 cm
= 3850 sq cm $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
∴ Area of the circle is 3850 sq cm.