## Τρίτη, 10 Οκτωβρίου 2017

### 2007 JBMO Shortlist G2 problem 2

Let$ABCD$be a convex quadrilateral with $\angle DAC=\angle BDC={{36}^{o}},\angle CBD={{18}^{o}}$ and $\angle BAC={{72}^{o}}$. If $P$ is the point of intersection of the diagonals $AC$ and $BD$, find the measure of $\angle AP D$.

proposed in aops here