Lets say we have ray over here that starts at point A and then goes through point B,and so we could,
call this ray(we could call,let me draw that a little bit straighter)we could call this ray AB.Ray AB
starts at A or has a vertex at A and lets say that there is alos a ray AC.So lets say that is sitting
right over there and then i can draw another ray that goes through C,so this is ray AC.and whats's interresting
anout thses two rays is that they have the exact same vertex.(they have the exact same vertex at A)
and in general waht we have when we have two rays with the exact same vertex,you have an angle,and
you 've probably,you 're probably already reasonably familiar with the concept of an angle which i believe