Circle A has a center at (5 ,2 ) and an area of 18 pi. Circle B has a center at (3 ,6 ) and an area of 27 pi. Do the circles overlap?

1 Answer
Feb 19, 2016

The circles do overlap (by 4.87 units)

Explanation:

Since Circle A has an Area =18pi,
Circle A has a Radius of r_A = sqrt(18) = 3sqrt(2)~~4.24
color(white)("XXX")(this follows from formua "Area" =pir^2)

Since Circle B has an Area =27pi
Circle B has a Radius of r_B=sqrt(27)=3sqrt(3)~~5.20

The distance between the center of A at (5,2) and the center of B at (3,6) is
color(white)("XXX")d=sqrt((5-3)^2+(2-6)^2)=2sqrt(5)~~4.47

Together the radii of circles A and B cover 4.24+5.20 = 9.34 of the line segment joining the centers of A and B.
Since this is greater than the actual length of the line segment joining A and B, the radii must overlap by 9.34-4.47=4.87 units.
graph{((x-5)^2+(y-2)^2-18)((x-3)^2+(y-6)^2-27)=0 [-14.11, 17.94, -3.74, 12.28]}