Đề cương toán hình, giúp mình với!

D

depvazoi

Kẻ DH//BM ($H\in AC$)
Ta có: CD là phân giác $\Delta ABC$(gt)
=> $\dfrac{AC}{BC}=\dfrac{AD}{BD}$
<=> $\dfrac{AD}{BD}=\dfrac{AH}{HM}$(HD//BM)
Mà $\dfrac{IC}{ID}=\dfrac{CM}{HM}=\dfrac{AM}{HM}$(MI//DH)
=> $\dfrac{IC}{ID}-\dfrac{AC}{BC}=\dfrac{AM}{HM}-\dfrac{AH}{HM}=\dfrac{HM}{HM}=1$ (đpcm)
 
Last edited by a moderator:
You must log in or register to reply here.
Top Bottom