Question

if the radius of circle decreases by 70%its area decreases by​

Answer 1

Answer:

91%

Step-by-step explanation:

Let original radius be r

Then original area=π$r^{2}$

New radius would be 100-70=30% of r

=3r/10

And area would be π*3r/10*3r/10

=π*9$r^{2}$/100

On comparison, we divide 9π$r^{2}$/100 by π$r^{2}$

We get it to be 9/100

=9% of the original area

Decrease=100%-9%

=91%

Hope this helps. Good day to you.