Difference between revisions of "2016 JBMO Problems/Problem 1"

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== Problem ==
 
== Problem ==
A trapezoid <math>ABCD</math> (<math>AB || CF</math>,<math>AB > CD</math>) is circumscribed.The incircle of the triangle <math>ABC</math> touches the lines <math>AB</math> and <math>AC</math> at the points <math>M</math> and <math>N</math>,respectively.Prove that the incenter of the trapezoid <math>ABCD</math> lies on the line <math>MN</math>.
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A trapezoid <math>ABCD</math> (<math>AB || CD</math>,<math>AB > CD</math>) is circumscribed.The incircle of the triangle <math>ABC</math> touches the lines <math>AB</math> and <math>AC</math> at the points <math>M</math> and <math>N</math>,respectively.Prove that the incenter of the trapezoid <math>ABCD</math> lies on the line <math>MN</math>.
  
 
== Solution ==
 
== Solution ==

Latest revision as of 03:18, 3 March 2019

Problem

A trapezoid $ABCD$ ($AB || CD$,$AB > CD$) is circumscribed.The incircle of the triangle $ABC$ touches the lines $AB$ and $AC$ at the points $M$ and $N$,respectively.Prove that the incenter of the trapezoid $ABCD$ lies on the line $MN$.

Solution

See also

2016 JBMO (ProblemsResources)
Preceded by
First Problem
Followed by
Problem 2
1 2 3 4
All JBMO Problems and Solutions