Question

If the radius of a circle is increased by 10%, by what per cent will its area increase ?​

Answer 1

Step-by-step explanation:

we know a=πr²

a is proportional to r²

∆a/a=2∆r/r

∆r/r×100=10

=1/10 =.1

∆a/a=2 × .1 ×100

20% approximately