Chứng minh ΔAHB = ΔAHD

cho tam giac ABC vuong tai A co AB nho hon AC dung AH vuong goc BC tren tia HC lay D sao cho HD=HB dungCE vung goc AD
a] cm tam giac AHB=tam giac AHD
b] cm goc BAH=gocACB
c] cm CB la phan giac goc ACE
cam on moi nguoi ve hinh nua nhek