Constrain any of the line types; line, line segment, vector, or polygon side, to a direction measured from the horizontal.
| 1. | Select  one of the line types listed above. |
| 2. | Click the Direction icon  . |
| 3. | Enter the constraint, real or symbolic. If you enter a real value, the line will be adjusted to reflect the constraint. |
Note: The angular units are displayed in the lower right of the screen. Change the default (Degrees or Radians) in the Edit / Settings menu.