I have two distinct line segments on a cartesian plane, which may or may not interest. The line segments are defined by their endpoints $((x_{1},y_{1}),(x_{2},y_{2}))$ and $((x_{3},y_{3}),(x_{4},y_{4}))$.
Now, imagine that the endpoints of these two line segments are connected such that the connections do not intersect. You should be imagining the formation of one triangle(when the two lines share an endpoint), two triangles(when the endpoint of one line is on the other line but not the other line's endpoint), three triangles(when one line goes through the other line but not one of it's endpoints), or a trapezoid(the lines do not touch).
Given a new point on the plane $(x_{5},y_{5})$, how can I tell if that point is within the bounds of the polygons created between the two lines?