如图,△ABC,AB=AC,AD=AE,AD⊥BC,求证;∠EDC=1/4∠BAC如图,△ABC,AB=AC,AD=AE,AD⊥BC,求证;∠EDC=1/4∠BAC

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如图,△ABC,AB=AC,AD=AE,AD⊥BC,求证;∠EDC=1/4∠BAC
如图,△ABC,AB=AC,AD=AE,AD⊥BC,求证;∠EDC=1/4∠BAC

AD=AE
∠ADE=(180-∠DAE)/2
∠EDC=90-∠ADE=∠DAE/2
AB=AC,AD⊥BC,
∠BAD=∠DAC
;∠EDC=1/4∠BAC