Straight Angle vs. Line

Date: 09/07/97 at 11:58:49
From: Andrew
Subject: Geometry angle question

My question is simple. Why is a straight angle (line) not considered 
an angle? 

Thanks a lot.

Andrew

Date: 09/13/97 at 21:09:47
From: Doctor Mike
Subject: Re: Geometry angle question

Hi Andrew,    

First of all, there is a difference between a line and a straight 
angle. A line is a piece of geometry, whereas an angle is a measure of 
how TWO lines come together.  

I like to visualize a straight angle as 2 lines going out from the 
same point, like ... 
    
       <----------------------*--------------------->  
  
The point is the "*" and the lines go to the left and to the right.
The straight angle (180 degrees) is a measure of how those 2 lines
come together.  So, a line is not an angle, BUT a straight angle is a 
fine angle. 

I hope this helps.   

-Doctor Mike,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/