Radius of the outer circle = 4 cms.
∴ Area of the outer circle = πr2
= 3.14 × 4 × 4
= 28.26 sq.cms
= 50.24 sq.cms
π = 3.14
Radius of the inner circle = 3 cms
∴ Area of the inner circle = πr2
= 3.14 × 3 × 3 = 28.26 sq. cms
Area of the remaining part = 50.24 – 28.26
= 21.98 sq.cms