Ve tam giac ABC. Goi M, N lan luot la trung diem AB,AC. G la trong tam cua tam giac ABC. Qua N ke duong thang song song voi CM, cat duong thang BC tai D. Ke Dx // BN, ke By // DN, Dx giao By tai E, ME giao BC tai I
a) Tu giac MNDC la hinh binh hanh
b) Tu giac BMCE la hinh binh hanh
c) A, G, I thang hang
d) Tia EN cat tia BA tai K. Chung minh AIEK la hinh thang
e) Tam giac ABC thoa man them dieu kien gi thi AIEK la hinh thang can?
Mong cac ban doc giup minh giai ho bai toan, xin tran trong cam on. ( Lop 8)
