Question

如图,将△ABC中,∠ACD是外角,BE平分∠ABC,CE平分∠ACD,求证:∠E=1\2∠A

Answer 1

∠E=∠ECD - ∠EBC

=12∠ACD - 1/2∠ABC

=12(∠ACD - 1/2∠ABC)

=12∠A