Question

in the adjoining figure the area enclosed between the concentric circles is 770cm².if the radius of the o
uter circle is 21 cm calculate the radius of the inner circle ​

Answer 1

Answer:

Let the radius of the inner circle be r cm. Then,

(π×21×21)−πr²=770

π(441−r² )=770

22/7 ×(441−r²)=770

r²=196

r=14 cm

Answer 2

Answer:

here is ur answer..hope it will help u