【安室透:273:∠ADC + ∠DCA + ∠DAC = 180°
∠ADC=130°
所以 ∠DCA + ∠DAC = 50°
AD、CD分别平分∠BAC和∠ACB
所以∠BCA =2∠DCA ,∠BAC = 2∠DAC
∠BCA + ∠BAC = 2(∠DCA+∠DAC) = 100°
∠BCA + ∠BAC + ∠B = 180°
所以 ∠B = 80°
因为 AB=AC
所以 ∠BCA=∠B = 80°
所以 ∠BAC = 180° - ∠BCA - ∠B = 20°
@katty猫kitty