Cau 13:Tam giac ABC co AB=5, AC =9 va duong trung tuyen AM =6...
Cau 13:Tam giac ABC co AB=5, AC =9 va duong trung tuyen AM =6. Tinh do dài canh B C.A A.27 B. √(17) C. √(129) D.22Lòi giǎi Chon A A596B MC Ta co: AM^2=(AC^2+AB^2)/2-(BC^2)/42 4=BC^2=4((AC^2+AB^2)/2-AM^2)=4((9^2+5^2)/2-6^2)...