How to find AC?
Use BPT theorem(Any of the following can be used to solve)
[tex]\\ \rm\rightarrowtail \dfrac{AC}{AB}=\dfrac{AY}{YX}[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{AY}{AC}=\dfrac{AX}{AC}[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{AY}{XY}=\dfrac{AC}{BC}[/tex]