Here's some basic hints that hopefully can get you started. Let us know if you are still have some additional questions (and if so, try to provide what you've found so far):

• We are given that $[CBD] = [BAE] = [ACF]$ so we also know that the ratios $\displaystyle \frac{[CBD]}{[ABC]} = \frac{[BAE]}{[ABC]} = \frac{[ACF]}{[ABC]}$.
• The height of $8$ and diagonal of length $10$ make us suspicious and we'd like to find (or construct) a 3-4-5 triangle. Try to do so in a convenient way by "moving" a diagonal.