The geometry package may be used as part of a class or another package you use in your document. The command geometry can overwrite some of the settings in the preamble. Multiple use of geometry is allowed and then processed with the options concatenated. Geometry flexible and complete interface to document dimensions. The package provides an easy and flexible user interface to customize page layout, implementing auto-centering and auto-balancing mechanisms so that the users have only to give the least description for the page layout. The geometry package has auto-completion mechanism that saves the trouble of specifying the page layout dimensions. For example, you can set usepackagewidth14cm, left3cmgeometry 3. In this case you dont have to set the right margin the details of auto-completion.