Geometry Definition of a Ray
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It Went That-A-Way
Definition of a Ray

 

 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

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