# Mickey Mouse?

Geometry Level 3

If $$a,b,$$ and $$c$$ are the side lengths of $$\triangle ABC$$ opposite to angles $$A,B,$$ and $$C,$$ respectively, and $$r_{1},r_{2},$$ and $$r_{3}$$ are the corresponding exradii, then find the value of

$\frac {b-c}{r_{1}} + \frac {c-a}{r_{2}} + \frac{a-b}{r_{3}}.$

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