Question

△ABC中,BA平分∠DBC,∠BAC=124°,BD⊥AC于D,求∠C的度数

Answer 1

∠DAB=∠ABC+∠ACB=180-124=56°

△ABD中,BD⊥AC,BD⊥AC,∠DAB+∠ABD=90°

BA平分∠DBC所以∠ABC=∠ABD

∠DAB=56°

∠ABD+∠DAB=90°

∠ABC=∠ABD

解得∠ABD=34° ∠ABC=34°

所以∠ACB=56°-34°=22°

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