Difference between revisions of "2007 IMO Problems/Problem 2"

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line <math>BC</math> at <math>G</math>. Suppose also that <math>EF=EG=EC</math>. Prove that <math>\ell</math> is the bisector of <math>\angle DAB</math>.
 
line <math>BC</math> at <math>G</math>. Suppose also that <math>EF=EG=EC</math>. Prove that <math>\ell</math> is the bisector of <math>\angle DAB</math>.
  
== Solution ==
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==Solution==
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{{alternate solutions}}
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{{IMO box|year=2007|num-b=1|num-a=3}}
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[[Category:Olympiad Geometry Problems]]

Revision as of 00:12, 9 October 2014

Problem

Consider five points $A,B,C,D$, and $E$ such that $ABCD$ is a parallelogram and $BCED$ is a cyclic quadrilateral. Let $\ell$ be a line passing through $A$. Suppose that $\ell$ intersects the interior of the segment $DC$ at $F$ and intersects line $BC$ at $G$. Suppose also that $EF=EG=EC$. Prove that $\ell$ is the bisector of $\angle DAB$.

Solution

Alternate solutions are always welcome. If you have a different, elegant solution to this problem, please add it to this page.

2007 IMO (Problems) • Resources
Preceded by
Problem 1
1 2 3 4 5 6 Followed by
Problem 3
All IMO Problems and Solutions