Extending a line with the Freehand & Brush Tool
After you have finished drawing a line you can extend it at any time. You can use any of line drawing tools (Freehand & Brush Tool, Pen Tool, Shape Editor Tool).
To extend a line with the Freehand & Brush Tool
1. Select the line (see Selecting objects).
2. Choose the Freehand & Brush Tool.
3. Move the mouse pointer over the end of the line - the pointer will change (see below).
4. Drag and move the mouse to create the new line section.
Dragging will extend an existing line