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MathNet 2017-part-03 — 176 problems (EN–VI) Question 96

Math Olympiad Vault · MathNet 2017-part-03 — 176 problems (EN–VI)

Question 96

In the given figure, $ABCD$ is a square paper. It is folded along $EF$ such that $A$ goes to a point $A'$ ($A' \neq C, B$) on the side $BC$ and $D$ goes to $D'$. The line $A'D'$ cuts $CD$ in $G$. Show that the inradius of the triangle $GCA'$ is the sum of the inradii of the triangles $GD'F$ and $A'BE$.

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