Question

Help me to do 10(b) answer​

Answer 1

Explanation:

Big circle:

R = radius = diameter ÷2 = 42 ÷ 2 = 21 cm

Area of big circle= πR²

`=(22)/(7)*21*21=22*3*21\\\\\\= 1386 \ cm^(2)`

Small circle:

Diameter of small circle = radius of big circle = 21 cm

r = 21/2 = 10.5 cm

Area of small circle = πr²

`=(22)/(7)*10.5*10.5 = 22 * 1.5*10.5\\\\\\= 346 .5 \ cm^(2)`

Area of shaded region = area of big circle - area of small circle

= 1386 - 346.5

= 1039.5 cm²