# Types of Lines

### Line:

• A line is a straight one dimensional geometrical figure which having no thickness and will be extended up to infinity in both the directions.
• Hence, we cannot measure the length of line. ### Line segment:

• Line segment is the portion of line but which is having two end point on both sides.
• The length of line cannot be measured but the length of line segment is measured as it is having finite length. ### Ray:

• Ray is also the portion of line which is having one end point and it extends up to infinity from other end.
• The starting point of ray is called as the vertex point.
• When two rays meet at a common vertex point then angle is formed. ## The types of lines are as follows:

1. Horizontal line:

• The straight line which is drawn from left to right or right to left and which is parallel to X- axis in Cartesian coordinate system is the horizontal line.
• The horizontal line is parallel to X-axis but it is having only y-intercept on the Y-axis as shown in figure.

2. Vertical line:

• The straight line which is in up and down direction and parallel to Y-axis is called as the vertical line.
• The vertical line has only x- intercept and no slope or which is undefined as shown in figure.

3. Intersecting line:

• When two or more lines crosses each other at a common point then these lines are called as intersecting lines. The common point at which they intersect is called as the intersecting point.
• Intersecting point lies on each line and it is common in all lines as shown in following figure.

4. Perpendicular line:

• When two straight lines intersect at a right angle to each other in a common point then it is called as perpendicular lines.
• The following figure shows the perpendicular lines which are having the slope m1 and m2.
• Then, m1= -1/m2

5. Parallel line:

• Parallel lines are the straight lines which do not intersect each other at any point and will be extended up to infinity in a plane.
• The following figure shows the parallel lines with slope m1 and m2.
• Then, for parallel lines,
• m1 = m2

6. Curved line:

• The lines which are not straight but somewhat bent are the curved line.
• The following figure shows the curved line.

7. Skew line:

• Skew lines are the lines which are not parallel and also not intersecting.
• Hence, they can exist only three or more dimensions.
• The following figure shows the skew line.

8. Dotted line:

• Dotted line is made up of a series of dots along a straight direction.
• The following figure shows the dotted line.

9. Diagonal line:

• Diagonal line is the line which is somewhat slant and join the two opposite corners of the shape.
• In following figure the line AB is the diagonal line. Fig: Types of lines