如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC=

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如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC=

如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC=
如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC=

如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC=
过点D作平行线段DE交AB于点E
∵D是BC中点,DE‖AC,AD⊥AC
∴E是AB中点,∠CAD=∠ADE=90°
又∵AB=2AC,DE‖AC
∴AC=2DE,即在Rt△ADE中,斜边AE=AC=2DE,则∠EAD=30°
∴∠BAC=∠DAC+∠DAB=90°+30°=120°,证毕