Given: △ABC, m∠B=90° AB=12, BC=16, BK ⊥ AC . Find: AC and BK.

DESPERATE! Please help! I know that AC is 20 if that helps. I have NO idea how to find BK. I will be so thankful for any help you can give. If you get the right answer I'll give max points and BRAINLIEST!!!! Thank you so much :)