The Pencil option allows you to draw a free-form line on the view. To use Pencil:
Select Pencil from the toolbar or the Add Tool sub-menu of the Tools menu.
Click and HOLD the left mouse button, and drag the mouse to draw a free-form line.
When you are finished, release the mouse button. Right-click and select Done or press Enter to add the Pencil line to the view.
After a Pencil line has been added, it can be moved, re-sized, formatted etc. See the Edit Tools Overview topic for details.
NOTE: the Pencil line is actually a polyline made up of a series of straight line segments. You can see this if you single click the left mouse button on the Pencil line. This will highlight all of the vertices which make up the line.