- #1

Gjmdp

- 148

- 5

## Homework Statement

Let AC=5 and BC=12. In the triangle ABC, with angle C=90, point M is in AC. A circumference with center M and radius r is tangent to AB and tangent to BC in C. Set r.

## Homework Equations

This should envolve basic trigonometry, and Thales' theorem; but not sure ( if I knew the equations for solving the problem, I would alredy knew the answer).

## The Attempt at a Solution

By Thales' Therem: AC/BC=(AC-r)/x; then: 5/12=(5-r)/x. But I don't know how to get x. I've tried many proportions and no one just works. I also tried the 2 Thales' theorem, and didn't work either. Let me tell I know the answer, r=12/5, and that this is not for any class, just found on internet, but I can't get to know how to solve it. If any help, appreciate :)[/B]