😂cho tam giac abc vuong tai a . tren canh bc lay mot diem d sao cho bd=ba . tia phan giac cua goc b cat canh ac tai diem e
a/ chung minh tam giac bea = tam giac bed
b/ qua c ve duong thang vuong goc voi be tai h , ch cat duong thang ab tai f. chung minh tam giac bhf= tam giac bhc
c/ chung minh 3 diem d e f thang hang