# Circle A has a radius of 2  and a center at (8 ,3 ). Circle B has a radius of 3  and a center at (3 ,2 ). If circle B is translated by <-2 ,6 >, does it overlap circle A? If not, what is the minimum distance between points on both circles?

Jun 15, 2018

$\text{no overlap } , \approx 3.6$

#### Explanation:

$\text{what we have to do here is compare the distance (d)}$
$\text{between the centres to the sum of the radii}$

• " if sum of radii">d" then circles overlap"

• " if sum of radii"< d" then no overlap"

$\text{before calculating d we require to find the new centre of}$
$\text{B under the given translation}$

$\text{under the translation } < - 2 , 6 >$

$\left(3 , 2\right) \to \left(3 - 2 , 2 + 6\right) \to \left(1 , 8\right) \leftarrow \textcolor{red}{\text{new centre of B}}$

$\text{to calculate d use the "color(blue)"distance formula}$

•color(white)(x)d=sqrt((x_2-x_1)^2+(y_2-y_1)^2)

$\text{let "(x_1,y_1)=(8,3)" and } \left({x}_{2} , {y}_{2}\right) = \left(1 , 8\right)$

$d = \sqrt{{\left(1 - 8\right)}^{2} + {\left(8 - 3\right)}^{2}}$

$\textcolor{w h i t e}{d} = \sqrt{49 + 25} = \sqrt{74} \approx 8.60$

$\text{sum of radii } = 2 + 3 = 5$

$\text{since sum of radii"< d" then no overlap}$

$\text{minimum distance "=d-" sum of radii}$

$\textcolor{w h i t e}{\times \times \times \times \times \times \times} = 8.6 - 5 = 3.6$
graph{((x-8)^2+(y-3)^2-4)((x-1)^2+(y-8)^2-9)=0 [-20, 20, -10, 10]}