Question 1154274
*[illustration similar_triangles.png]

Triangle ACF ~ triangle ABC

AC/AB =AF/AC

12/13 = AF/12  
AF =11.08

In BCF and BAC

BC/AB = BF/BC

Plug values to get BF = 1.92

CF^2 = BF * AF   ( geometric mean property)

Plug values to get CF = 4.61