Circle A has a radius of 3 and a center of (5 ,9 ). Circle B has a radius of 4 and a center of (1 ,2 ). If circle B is translated by <3 ,2 >, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Feb 9, 2018

R_A + R_B color(green)((7)) > vec(O_AO_B) color(blue)((4.123)), the two circles A & B overlap.

Explanation:

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Circle A O_A (5,9), R_A = 3, Circle B O_B (1,2), R_B = 4

O_B translated by (3,2)

New O_B = ((1+3),(2+3)) => ((4),(5))

Distance vec(O_AO_B) = sqrt((4-5)^2 + (5-9)^2) = sqrt17 ~~ 4.123

Sum of radii R_A + R_B = 3 + 4 = 7

Since R_A + R_B color(green)((7)) > vec(O_AO_B) color(blue)((4.123)), the two circles A & B overlap.