Question

如图,直线DE与△ABC的边AC,AB分别交于点F,点E,且与BC延长线交于点D.∠A=40°,∠D=25°,DE⊥AB

Answer 1

∵∠ABD=180°∠A-∠BDE=180°-90°-25°=65°

∴∠ACB=180°∠A-∠ABD=180°-40°-65°=75°

∴∠ACD=180°-∠ACB=180°-75°=105°