Cho tam giac ABC can tai A, duong trung tuyen AM. Cho biet AB= 13cm, BC= 10cm.
a. Tinh do dai AM
b. Tren AM lay diem M sao cho GM=1/3AM. Tia BG cat AC tai N. Chung minh: NA=NC
c. Tinh do dai BN
d. Tia CG cat Ab tai L. Chung minh rang LN//BC.
May tinh cua minh ko the viet co dau nen cac ban thong cam. Giai jup minh vs a, minh ko hiu. Thanks a lot!