By showing the text boundary around the document content, you can visually analyze the width/height of the paper, and find out that how the text is dispersed in the Word 2010 document. It also helps in setting images within required document area.
For inserting text boundary, On File menu, click Options.
It will open up Word Options, from left sidebar, select Advanced, and from main window under Show document content, enable Show text boundaries option. Click OK to continue.
This will insert text boundary in the document.
As shown in the screenshot above, you can know the basic text structure and fill the voids promptly.