Circle A has a center at #(1 ,4 )# and an area of #28 pi#. Circle B has a center at #(7 ,2 )# and an area of #8 pi#. Do the circles overlap? If not, what is the shortest distance between them?

1 Answer
Mar 10, 2016

circles overlap

Explanation:

Require to find the radii of circles and the distance between their centres.

Calculate distance between centres using #color(blue)" distance formula "#

# d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)#

where #(x_1,y_1)" and" (x_2,y_2)" are 2 coordinate points "#

let #(x_1,y_1)=(1,4)" and " (x_2,y_2)=(7,2)#

#rArr d=sqrt((7-1)^2+(2-4)^2 )= sqrt(36+4)=sqrt40 ≈ 6.325#
#color(red)"--------------------------------------------------------------"#
To calculate radii , use area of circle # = pir^2#

circle A : # pir^2 = 28pi rArr r^2 = 28 " and " r = sqrt28 ≈ 5.292#

circle B : #pir^2 = 8pi rArr r^2= 8" and " r=sqrt8 ≈ 2.828#

now: radius A + radius B > distance between centres

hence circles overlap