Maths Olympiad Prep

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Geometry Difficulty 4.6 AIME Prove it JBMO

Problem:
A triangle with area 20032003 is divided into non-overlapping small triangles. The number of all the vertices of all those triangles is 20052005. Show that at most one of the smaller triangles has area less or equal to 11.

Solution

Solution:
Since all the vertices are 20052005, and the vertices of the big triangle are among them, it follows that the number of the small triangles is at least 20032003. So, it follows that at least one of the small triangles has area at most 11.

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