因为BD是△ABC的角平分线故：∠CBD=∠ABD=1/2∠ABC因为DE是BC的垂直平分线故：DB=DC,∠CDE=∠BDE=1/2∠BDC故：∠CBD=∠C=∠ABD=1/2∠ABC因为∠A＝90°故：∠C+∠ABC=1/2∠ABC+∠ABC＝90°故：∠ABC＝60°故：∠BDC=1...