三角形ABC,角ACB=90度E,D分别是AB上的点,AE=AC,BD=BC,求角ECD的度数

已知,AE = AC ,BD = BC ,可得：∠AEC = ∠ACE ,∠BDC = ∠BCD ；因为,∠ECD = 180°-(∠AEC+∠BDC) = 180°-(∠ACE+∠BCD) = 180°-(∠ACD+∠ECD+∠BCE+∠ECD) = 180°-(90°+∠ECD) = 90°-∠ECD ,可得：2∠ECD = 9...