IMO Shortlist 2005 G6

Discussion on International Mathematical Olympiad (IMO)
User avatar
*Mahi*
Posts:1175
Joined:Wed Dec 29, 2010 12:46 pm
Location:23.786228,90.354974
Contact:
IMO Shortlist 2005 G6

Unread post by *Mahi* » Sat May 19, 2012 8:39 pm

The median $AM$ of triangle $ABC$ intersects the incircle $\omega$ at $K$ and $L$. The lines through $K$ and $L$ parallel to $BC$ intersects $\omega$ again at $X$ and $Y$. The line $AX$ and $AY$ intersect $BC$ at $P$ and $Q$. Prove that, $BP=CQ$.
Please read Forum Guide and Rules before you post.

Use $L^AT_EX$, It makes our work a lot easier!

Nur Muhammad Shafiullah | Mahi

User avatar
*Mahi*
Posts:1175
Joined:Wed Dec 29, 2010 12:46 pm
Location:23.786228,90.354974
Contact:

Re: IMO Shortlist 2005 G6

Unread post by *Mahi* » Sat May 19, 2012 9:04 pm

Hint:
Yufei Zhao - geolemmas, lemma 7.
Also, "Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?"
Please read Forum Guide and Rules before you post.

Use $L^AT_EX$, It makes our work a lot easier!

Nur Muhammad Shafiullah | Mahi

User avatar
Phlembac Adib Hasan
Posts:1016
Joined:Tue Nov 22, 2011 7:49 pm
Location:127.0.0.1
Contact:

Re: IMO Shortlist 2005 G6

Unread post by Phlembac Adib Hasan » Tue Apr 30, 2013 11:52 pm

Yeah, Zhao is always awesome. I proved that lemma (also the whole problem) using projective geometry. This solution is (almost) the same as mine. So no need to post again.

Post Reply