is a way to refer to the line segment with endpoints A and B. Without the overline, refers to the measure of the line segment
Usage example: Let's say you have two line segments and and you know that the measures of these two line segments are the same. Then you can write @ which means "line segment AB is congruent to line segment CD" or you could write which means "the measure of line segment AB is equal to the measure of line segment CD". However, it would be wrong to say . In other words the statement "the line segment AB is equal to the line segment CD" is nonsense.
John
My calculator said it, I believe it, that settles it
