Here in AD and BE are medians.

Hence, in ∆ABC, we have:
AC = AE + EC

But AE = EC … as E is midpoint of AC

∴ AC = 2EC …(1)

Now in ∆BEC,

DF || BE

Also, EF = CF … by midpoint theorem, as D is the midpoint of BC

But,

EC = EF + CF

∴ EC = 2 CF …(2)

From 1 and 2, we get,

AC = 4 CF

∴