#### Answer

When r=2:
$A=3.14*4$
$A=12.56$
When r=3:
$A=3.14*9$
$A=28.26$
When r=7:
$A=3.14*49$
$A=153.86$
When r=10:
$A=3.14*100$
$A=314$

#### Work Step by Step

The formula for Area is $3.14r^2$; simply substitute values for r to find that circle’s radius.