Rt△ABC中,∠ACB=90°,M是AB边的中点 所以AM=CM =BM ∠CAB=∠ACM∠CAB=90- ∠ABC ∠BCH=90- ∠ABC 所以 ∠CAB= ∠BCH所以 ∠BCH =∠ACM 有CD平分,∠ACB ,∠ACD = ,∠B CD,∠ACD -∠ACM = ∠B CD-∠BCH 即 ∠HCD=∠MC...