Draw a line parallel to a curve

1. Choose Keypoint Curve Tools > Lines > Parallel Line.
2. Click the curve to which the new line will be parallel.
   
   • Guidelines are added for the curve, allowing you to line up the start and/or end points of the new line.
   • If you click a curved line, the new line is parallel to the tangent where you click.
3. Click the start point of the parallel line, or type a 3D coordinate to place the point exactly.
   

   As you drag the start point, the Parallel Line tool displays the distance between the lines in current linear units.

4. Click the end point of the parallel line, or type a 3D coordinate to place the point exactly.
   

   As you drag the end point, the Parallel Line tool displays the length of the line in current linear units.

Draw a line at an angle to a curve

1. Choose Keypoint Curve Tools > Lines > Line at Angle.
2. Click the start point of the new line on the curve from which it will angle off.
   

   If you click a curved line, the new line is drawn at an angle to the line that passes through the end point of the curve.

3. If you want to project the line at an exact angle, type the value of the angle and press (Windows) or (Mac). The Line at Angle tool adds a new guideline at that angle.
   
4. Click the end point of the new line.
   

   As you drag the end point, the Line at Angle tool displays the angle in current angular units (degrees by default).

What if...?

I want to edit the coordinates, parallel distance, or angle after I create a line?

Make sure the line is selected, then choose Windows > Information > Information Window and change the Line Offset or Rel Angle attribute.

The relationships between keypoint lines are maintained until you manually reshape one of the lines.