Perpendicular

 
Creates a line perpendicular to an existing line.

Tip: This tool creates a line from an existing line. To create a perpendicular line to a line, you can use the "J" SEKE (see Running and Local Snaps.

1. Select an existing line.
   
2. Select the point on the existing line where the perpendicular line will start. You can select a point past the endpoints.
   
3. Select a third point to set the length of the perpendicular line, or enter the length in the Inspector Bar.
   

 
Local menu option:

Limit to Segment: The perpendicular line cannot extend past the endpoints of the existing line.

Tip: To draw a line perpendicular to an arc or circle, draw a single Line from the center of the arc or circle to its destination, then trim the line.