已知：CD=BC,AB⊥BD,ED⊥BD.求证：AB=DE证明：∵AB⊥BD,ED⊥BD (已知)∴∠ABC=∠EDC (垂直定义)在△ABC与△EDC中∠ABC=∠EDB (已证) CB=DC (已知) ∠ACB=∠ECD (对顶角相等) ∴△ABC≌△EDC (ASA)∴AB=ED (全等三角...