T
tieuthu_bongbong


Cho tam giac ABC vuong can o A . Goi D la mot diem nam trong tam giac sao cho goc DBC=goc DCA= 30*.
C/M : tam giac ACD can , tinh cac goc cua tam giac can do.
C/M : tam giac ACD can , tinh cac goc cua tam giac can do.