Question

（1）如图①，已知△ABC中，∠B > ∠C，AD⊥BC于D，AE平分∠BAC，试证明：∠DAE = (∠B -

Answer 1

（1）∠DAE = ∠BAE - ∠BAD =

∠BAC - (90° - ∠B)

=

(180° - ∠B - ∠C) - 90° + ∠B =

(∠B - ∠C) ；

（2）∠DFE =

(∠B - ∠C), 理由“略”；

（3）∠DFE =

(∠B - ∠C). ，理由“略”