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如图所示,已知△ABC中,∠BAC=90°,AB=AC,∠BAD=30°,AD=AE,则∠EDC的度数为()A.10°B.15°C.20°D.30°
如图所示,已知△ABC中,∠BAC=90°,AB=AC,∠BAD=30°,AD=AE,则∠EDC的度数为()
A.10°
B.15°
C.20°
D.30°
1回答
2020-03-0423:12
如图所示,已知△ABC中,∠BAC=90°,AB=AC,∠BAD=30°,AD=AE,则∠EDC的度数为()A.10°B.15°C.20°D.30°
如图所示,已知△ABC中,∠BAC=90°,AB=AC,∠BAD=30°,AD=AE,则∠EDC的度数为()
A.10°
B.15°
C.20°
D.30°
∵△ABC中,∠BAC=90°,AB=AC,∴∠B=∠C=90°2=45°,∵△ABD中,∠B=45°,∠BAD=30°,∴∠ADC=∠B+∠BAD=45°+30°=75°,∵∠BAC=90°,∠BAD=30°,∴∠DAC=90°-30°=60°,∵AD=AE,∴∠DAE=∠DEA=60°,∴...