



So now
we've got a point.









But
points by themselves are pretty boring. 





So how
can we make it less boring? 





We can
run a straight line out from the point in some direction 











OK,
What's the arrow for? 





The arrow
means that the line goes on forever. 


Our
screen or piece of paper doesn't go on forever, 


so we
can't draw the whole line. 





So to
show that it goes forever, 


we draw
the arrow at the end of the part we draw. 





So what
do we call this point with a line coming out 


that goes
on forever? 


Well,
math types really like science fiction stories. 


They
thought that it looked like one of those alien death rays, 


so the y
called it: 





A RAY






And said: 


A ray is
a point with a line coming out of it in some direction 


that goes
on forever. 





copyright 2005 Bruce Kirkpatrick 
