Question

[Nguyen hai dang]

∆ABC vuong tai A( AN nho hon AC)

AD=AB, AC=AT

AH vuong goc voi BC tai H, HA cat DE tai K

a) ∆ABC=∆ADE

b) goc BAH=goc ACH

c) K la trung diem cua DE

d) BD song song CE va BD+CE=BE√2