CHO ABC CÓ TRUNG TUYẾN AM, TÌM KHẲNG ĐỊNH ĐÚNG

Câu 7: Cho

^

ABC có trung tuyến AM, tìm khẳng định đúng:







1

(

)

AM



2

AB AC



A.

^

^

^

^

^

^

^

^

^

^

^

^

^

^

^AM

^

^

^

^

^

^

^

^

^

^

^

^

^

^

^

^AB

^

^

^

^

^

^

^

^

^

^

^

^

^

^

^

²

^BM

B.



 

AM



2

AB AC



AM



2

AB AC



D. C. ; DC b ; khi đó các