Rays are a special type of construction line with only one end point extending infinitely in one direction.

Angular Ray

1. Select a point for the end of the ray will pass. Select a second point, or enter the slant in the Inspector Bar.
   
   
2. The ray is created, with the properties assigned to the construction layer.

Hor izontal Line, Vertical Line

1. Select the point through for the end of the ray.
2. Continue creating ray lines of the same type, and select Finish when done.

Local menu options: 
Flip: the Flip option changes the direction of the ray 180 degrees.