I have previously posted about using the LENGTHEN command, which is helpful, but the LENGTHEN command doesn’t work on polylines. Here’s how to lengthen a polyline segment whether it is an endpoint or a vertex.

The examples shown in this tip use the dynamic grips that are available in AutoCAD 2011 & 2012 by hovering over a grip.

Here’s how:

Polyline Endpoint:

• Select the polyline
• Hover over the endpoint grip that you want lengthened
• Select “Stretch” or “Stretch Vertex” (depending on version)
• B <enter> to specify a base point
• Select the endpoint grip where you initially hovered over
• Either enter EXT <enter> or shift right-click and select the “extension” osnap
• hover over the end point and pull in the direct that you want to lengthen (you should see the dotted line that shows you that your are aligned with the line).
• Enter the distance to be lengthened <enter>

Polyline Vertex: (middle of polyline)

• Select the polyline
• Hover over a vertex grip that you want lengthened
• Select “Stretch” or “Stretch Vertex” (depending on version)
• B <enter> to specify a base point
• Select the endpoint grip where you initially hovered over
• Either enter EXT <enter> or shift right-click and select the “extension” osnap
• Hover over the end point and pull in the direct that you want to lengthen. You should see the dotted line that shows you that your are aligned with the line. Because a vertex shares 2 line segments there are 2 extension options (as seen below). Simply move your cursor in the direction to specify which line segment you want to lengthen.
• Enter the distance to be lengthened <enter>