Question

the circumferences of two circles are in the ratio of 1 : 3 . find the ratios of their areas .
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Answer 1

Answer:

Perimeter of two circles are in ratio 1:3 so if you take R=3,r=1. then area of circles are in the ratio pir^2:piR^2 so pi pi cancel so 1:3^2 that is 1:9

Answer 2

Answer:

Step-by-step explanation:

the circumferences of two circles are in the ratio of 1 : 3

$\frac{2\pi R }{2\pi r} =\frac{1}{3}$

$\frac{R }{r } =\frac{1}{3}$

the ratios of their areas =

=$\frac{\pi R^{2} }{\pi r^{2} }}$

=  $\frac{R^{2} }{r^{2} }$

= $(\frac{1}{3} )^{2}$

= $\frac{1}{9}$