Circle A has a radius of 4 and a center of (6 ,2 ). Circle B has a radius of 2 and a center of (5 ,3 ). If circle B is translated by <-2 ,2 >, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Apr 6, 2016

The degree of overlap is

6-3sqrt(2)~~1.757 to 3 decimal places

Explanation:

For circle A
Let the centre be C_a -> (6,2)
Let radius be R_a -> 4

For circle B
Let the centre be C_b->(5,3)
Let the radius be R_b->2

Let distance between centres be D

C_b translated by <-2,2 >

=> C_b ->(5-2,3+2)

=> C_b ->(3,5)
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(blue)("Determine final distance between centres")

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

D=sqrt((3-6)^2+(5-2)^2)

D=sqrt((-3)^2+(3)^2)

color(blue)(D=sqrt(18) = 3sqrt(2))
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(blue)("Determine if circles overlap")

For this to be true we need D < R_a+R_b

R_a+R_B = 4+2=6

3sqrt(2)<6 so they do overlap

The degree of overlap is

6-3sqrt(2)~~1.757 to 3 decimal places