Using theorem 6.3.7, we obtain that $AB \times AC = AF^2$ and $AD \times AE = AF^2$. Using substitution, we obtain: $AC \times AB = AE \times AD$
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.