Question

Find the area of the circles of following radii. a) 7 cm b) 10.5 cm c) 21 m

Answer 1

As we know that :

$Area \: of \: Circle \: \\ \\ \pi {r}^{2} \: where, \: r = Radius \: of \: Circle$

1) Radius = 7 cm Then, Area :

$\frac{22}{7} \times 7 \times 7 \\ \\ = > 154 \: {cm}^{2}$

2) Radius = 10.5 cm then, Area :

$\frac{22}{7} \times 10.5 \times 10.5 \\ \\ = > 346.5 \: {cm}^{2}$

3) Radius = 21 m then, Area :

$\frac{22}{7} \times 21 \times 21 \\ \\ = > 1386 \: {cm}^{2}$

Answer 2

Step-by-step explanation:

by using formula pai r²

22/7*7*7

22*7

154

do other two also like this