Draw Construction Lines
 
 
 

You can create construction lines that extend to infinity in one or both directions. Construction lines that extend in one direction are known as rays. Construction lines that extend in both directions are known as xlines. These construction lines can be used as a reference for creating other objects. For example, you can use construction lines to find the center of a triangle, prepare multiple views of the same item, or create temporary intersections that you can use for object snaps.