A pair of points is selected at random inside a unit circle and a line segment is drawn joining the two. Another pair is selected and a second line segment is drawn. Find probability that the two segments don't intersect.
I don't have a clue where to start with this one. I assumed the first pair but I'm not able to come up with the condition for the two segments to not intersect. Please help me out. Thank you.
Here is an example of a possible position of the segments -