Rays

A ray is a part of a line.  It has only one endpoint and extends indefinitely in only one direction.

Any point on a line divides it into two parts each called a ray. In the figure below, M divides line AB into two rays.

Thus, each ray is limited from one end and extended from the other end indefinitely. The limited end is called an initial point and the other end is called a terminal point. A ray is denoted by the labels of its endpoints with the sign "" above. In labeling a ray, the initial point must come first. A ray is also called a half-line.

This figure represents a ray.

We name this .

This next image would be named .

Practice

Name the ray:            

 

Name the ray: