Question

已知∠MAN=60°,AP为∠MAN的平分线,在边AM、AN上分别取点B、C使AB=AC,在AP上取点D,使∠BDC=1

Answer 1

AP为∠MAN的平分线,AB=AC,∠BDC=140°,则∠BDA=∠CDA=70°,

则∠ABD=180°-30°-70°=80°

或 ∠ABD=70°-30°=40°