# Ray

## Ray

Set of points on a line that are located on the same side of a point O on the line called the origin or endpoint of the ray.

### Notation

A ray is named by using the letter that represents its endpoint followed by a second letter that represents another point on the ray.

This is $$\overrightarrow{OD}$$:

Opposite rays are rays that have the same origin and that extend in opposite directions.

### Properties

• Every point on a line divides the line into two opposite rays.
• Two opposite rays form a straight angle.