Circle A has a center at #(2 ,3 )# and an area of #8 pi#. Circle B has a center at #(13 ,7 )# and an area of #54 pi#. Do the circles overlap?

1 Answer
Mar 24, 2016

This straightforward application of distance formula and comparing of the radiuses.
#R=10.18 < D_((B-A))=11.7# so no overlap

Explanation:

This straightforward application of distance formula and comparing of the radiuses. First let calculate the radii:
Let A(2,3) and B(13,7)
#r_A = pir^2 = 8pi => r=2sqrt(2)#
#r_B = pir^2 = 54pi => r=3sqrt(6)#
so the sum of the radii, #R = r_B+r_A=2sqrt(2)+3sqrt(6)#
#R = sqrt(2)(2+3sqrt(3))#

Now use the distance formula to find the distance from the center of the circles:
#D_((B-A)) = sqrt((13-2)^2+(7-3)^2)=sqrt(137)#

Now #R=10.18 < D_((B-A))=11.7# so no overlap