Answer:

π(441±0.2)

Explanation:

Given :

Radius = 21cm

Error in Radius = 0.1cm

We know that,

Area of circle = πr² , With r being radius,

Representing error with ∆,

=> ∆r = 0.1cm,

Let area be represented by A

=> A = πr² = π(21)² = 441π cm²

=> ∆A = 2π (∆r)

If you don't know how this is formed, Kindly refer your text book in the context of error, or simply you can apply differentiation to A with respect to r

=> ∆A = 2π(0.1) = 0.2π

=> Area with error = 441π ± 0.2π = π(441±0.2)

Therefore the answer is π(441±0.2)

Hope you understand,

If you still have any query kindly comment.

Thanking you,

Bunti 360 !