To extend a straight line

1. Double-click the line you want to extend.

2. Click the Simple Line Tool in the toolbox.

3. Click the Parallel button or the Perpendicular button in the ribbon.

4. Point to the end of the line you want to extend, and drag to extend line.

If you do not see the toolbox or the ribbon, click Toolbars on the View menu, and then click the Toolbox and Ribbon items.