Margins in a document are the white area that surrounds the text in your file. They appear at the top, bottom, left and right. While the default margins are usually ok, you sometimes have to change them. This is how it works:
Controlling Borders in Google Docs
Controlling margins in a document is a simple process that you can do in several ways: using the ruler or the menu bar.
Note: Changing the margins affects each page of the document. You can not change the margins of a single page separately.
Controlling Margins with the Ruler
When you open your file, look at the rulers at the top and left of the document. The upper ruler controls the left and right margins, the other ruler controls the upper and lower margins. The gray area on the ruler displays the current border.
The borderline is the line on the ruler between the border and the usable area of the document. Click on the borderline and drag to adjust the fill. The default setting is 1 inch or 2.54 cm (depending on the unit used).
Notice that the top border line hides behind the blue line and the blue arrow. These are the indentation indicators that allow you to control the indentation of the paragraphs of your document.
Repeat this step for each page you want to customize.
Google Docs changes the border dynamically as you row with the lines of the ruler.
Controlling Margins Using the Menu Bar
You can also set margins by using menu commands instead of dragging the border line to the border ruler.
Open the File menu and click Page Setup.
In the Page Setup window, enter the desired edge changes and click OK.
That's all it takes! You are now the master of your domain, and the margins of your document are under your complete control.