:D:Dcho hinh chop SABC.Day vuong tai B, AB=a , BC=acan3.((SBC),(ABC))=60.G la trong tam cua tam giac SBC.Ke duong thang d qua G, d//BC, d x SB=M,d x SC=N. a, Tinh Vs.amn b,Vs.amn voi truong hop d ko // voi BC day ai lam dc thi lam ho di...