Problem

Source: JBMO Shortlist 2013 C2

Tags: rectangle, combinatorics, combinatorial geometry



In a billiard with shape of a rectangle $ABCD$ with $AB=2013$ and $AD=1000$, a ball is launched along the line of the bisector of $\angle BAD$. Supposing that the ball is reflected on the sides with the same angle at the impact point as the angle shot , examine if it shall ever reach at vertex B.