Line question in C#

Question

Hi all, I am not exactly sure where even to start I have an in put value that would = X on a X Y graph I need to draw a line that would intersect that value of X that has a random slope then i need to get two (or more) random X,Y points from that line. I don't actually need to display any of this it could all be done "internally" all I really need is the output. If you can help thanks and if you only have a suggestion thank too.