Line Segments
Definition: Line Segment
A line segment is a curve which has no curvature and has a parametrization of the form .
NOTATION
If and , then we denote the line segment as
Extension
Theorem: Extension of a Line Segment
For each line segment there exists one and only one straight line which contains , i.e. .
PROOF
TODO
Definition: Extension of a Line Segment
The extension of a line segment is the unique straight line which contains it.
Midpoint
Definition: Midpoint
The midpoint of a line segment is the point which divides it into two congruence line segments.