The ratio of the radius of two circles is 1: 3, and then the ratio of their areas is?
1:3
1:6
1:9
1:5
Explanation:
$r_{1}r_{2}$ = 1 : 3
$ \pi r_{1}^2$ :$ \pi r_{2}^2$
$r_{1}^2 $:$ r_{2}^2 $= 1:9
Next Question
The radius of the two circular fields is in the ratio 3: 5 the area of the first field is what percent less than the area of the second?