# Lines, Segments and Rays

What are Rays, Lines and Line Segments?

A line is a thin straight mark made by a pencil and it extends indefinitely in both the directions. Here is the figure of a typical line.

Image

A ray starts at one point and goes indefinitely in one direction. Here is the figure of a ray.

image

We represent a ray by $\vec{AB}$. It is also shown in the following diagram. It tells us that the ray starts at point $A$ and goes indefinitely in one direction.

image

The point at which the ray begins is called the end point of the ray. Here, $A$ will be the endpoint of this ray. We should note that this particular ray cannot be written as $\vec{BA}$.

A line segment is the fixed part of a line. It has a specified length and does not extend indefinitely in both the directions. If the end points are labelled as $A$ and $B$ then we can call the line segment as AB or $\bar{AB}$ or $\bar{BA}$.

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What is the difference between a line and a segment?

The difference between a line and a segment can be tabulated as follows:

Line |
Line Segment |

A line goes on infinitely in both the directions | A line segment is contained by the endpoints |

The length of a line is infinite and cannot be measured. | We can measure the length of line segment. |

The symbol of a line is $\vec{}$. | A line segment is represented by the symbol $\bar{}$ . |