已知:AE┴BC CD┴AB
求证:ΔEDH~ΔCAH
∵AE┴CB CD┴AB
∴∠HEC=∠HDA=90°
∵∠CHE=∠AHD
∴ΔCHE~ΔADH
∴CH/AH=EH/DH
又∵∠AHC=∠DHE
∴ΔAHC~ΔDHE