Question

如图,在Rt三角形ABC中,角BAC=90度,AD垂直于BC,AE平分角BAC,若AB=15,BD=9,求：BC,AC,

Answer 1

如图,过点E作EF⊥AB于点F∵∠BAC=90°,AD⊥BC∴∠ADB=∠BAC∵∠B=∠B∴△BAC∽△BDA∴BD/BA=BA/BC∴BC=BA²/BD=15²/9=25∴AC=√(BC²-BA²)=20∵EF⊥AB∴EF∥AC∴△BAC∽△BFE∴BF/EF=BA/AC=15/20=...