A line segment can be defined as a part of line that is bounded by two points. The points are called the end points of the line segment.

Consider a line, denoted by L. Let A and B be two points on the line. Then, the line segment betweenA and B, denoted by $\overline{AB}$, contains the end points A and B, every point on the line between A and B.
Line Segment

Line Segments can represent the sides of a triangle or a polygon and the diagonals. On the basis of it, the line segments can be of the following types:
  • Diagonal Line Segment
  • Horizontal Line Segment
  • Vertical Line Segment

Here is the description of all the above mentioned types of line segments:

Diagonal Line Segment: The line segment that cuts diagonally from one corner of a square or rectangle to its opposite corner is called the Diagonal Line Segment. The slope of a diagonal line segment can be positive or negative and it cuts the square or rectangle into two congruent triangles.

Diagonal Line Segment

In the above figure, $\overline{AD}$ is a diagonal line segment with positive slope and it partitions the rectangle $\square$ABDC into two congruent triangles $\Delta$ABD and $\Delta$DCA; and $\overline{BC}$ is a diagonal line segment with negative slope and it partitions the rectangle $\square$ABDC into two congruent triangles $\Delta$ABC and $\Delta$DCB.

Horizontal Line Segment: Horizontal Line Segment is a line segment in the Coordinate Plane with all points on the line segment share the same y-coordinate. In the figure, $\overline{AB}$ is a horizontal line segment.

Vertical Line Segment

Vertical Line Segment: Vertical Line Segment is a line segment in the Coordinate Plane, with all points on the line segment share the same x-coordinate. In the figure, $\overline{AC}$ is a vertical line segment.