2024 SSMO Accuracy Round Problems/Problem 4

Problem

Right triangle $ABC$ has a right angle at $C$ and hypotenuse $1$. Let points $D$ and $E$ lie on $AC$ such that $\angle BDC=\angle BEC=45^{\circ}$. $A,D,C,$ and $E$ are colinear in that order. Given that $EA=13DA$, the area of $\triangle ABC$ can be expressed as $\frac{m}{n}$ for relatively prime $m$ and $n$. Find $m+n$.

Solution