Problem C. 1295. (May 2015)
C. 1295. The angles at vertices \(\displaystyle C\) and \(\displaystyle D\) of a quadrilateral \(\displaystyle ABCD\) are equal, and the intersection \(\displaystyle E\) of the interior angle bisectors drawn at vertices \(\displaystyle A\) and \(\displaystyle B\) lies on the side \(\displaystyle CD\). Prove that \(\displaystyle E\) bisects side \(\displaystyle CD\).
(5 pont)
Deadline expired on 10 June 2015.
Statistics:
58 students sent a solution.  
5 points:  52 students. 
3 points:  2 students. 
1 point:  2 students. 
0 point:  2 students. 
