Vertical fences are simple and traditional, but you can change up your yard by turning this idea on its side with a sleek, ...

To add a horizontal line to an existing document, click the File tab, select "Open" and browse to the document. Otherwise, Word opens a new page for you to work with.

Horizontal lines go left and right. Vertical lines go up and down. Parallel lines are a fixed distance apart and will never meet, no matter how long they are extended.