Cannot understand what this proposition is saying

[rxh140630]

Homework Statement

On the same straight-line, two other
straight-lines equal, respectively, to
two (given) straight-lines (which meet)
cannot be constructed (meeting) at a
different point on the same side (of
the straight-line), but having the
same ends as the given straight-lines

Relevant Equations

Euclids element's

can someone please explain to me how a straight line has a side? this is so frustrating

 

[rxh140630]

never mind I guess this thread might as well be deleted now.

Draw a vertical line, there is going to be a left side and a right side.

The figure that comes with the book confused me into questioning such a simple thing