Answers

2016-06-01T01:26:13+08:00
     area of circle     A    = π r²
     thus   49  =  π r²
     if the radius is increased by a factor of 3
        the new radius  =  ( 3 r)²  =  9 r²
       therefore the area has been increased by 9  times
        the new area   A  =   49*9   =  441m²
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