- I have the coordinates of the area (Workspace)
- I have the coordinates of the obstacles(Every point of outline of every obstacle)
- I'm drawing lines to join each point (obstacles extremities and area extremities)
- I have the coordinates of the lines between obstacles and between obstacles and workspace

I need an I idea of an algorithm to form valid traingles. I will attach two pictures to be more exact.

I'm in the situation of the first picture, I have the draw,coordinates, but I can't find an algorithm to find which 3 lines can form a triangle.

The coordinates of points are keept in generic lists List<Point> and lines of obstacles,workspaces and lines are separated kept in List<Line>

Thanks