Question 874571
Visual Hint:


<img src = "http://i150.photobucket.com/albums/s91/jim_thompson5910/2_zpsfab78abd.png">


If you focus on one right triangle, you get


<img src = "http://i150.photobucket.com/albums/s91/jim_thompson5910/3_zps69b31842.png">


Use the Pythagorean Theorem to solve for 'c'