BDMO National Junior 2018/8
Posted: Tue Jan 08, 2019 1:59 pm
In triangle $\triangle ABC$, $AB=10$, $CA=12$. The bisector of $\angle B$ intersects $CA$ at $E$, and the bisector of $\angle C$ intersects $AB$ at $D$. $AM$ and $AN$ are the perpendiculars to $CD$ and $BE$ respectively. If $MN=4$, then find $BC$.