Bouncing Ball in Triangle

For every acute triangle, there is a path so that a ball can bounce indefinitely.[br]1. What is the relationship between point [i]H[/i] and triangle [i]ABC[/i]?[br]2. What is the relationship between point [i]H[/i] and path of the bouncing ball?
Reference:[br]https://en.etudes.ru/sketches/billiard-trajectories/

Information: Bouncing Ball in Triangle