There are two basic page templates, "Left Sidebar" and "Right Sidebar". The areas on the page will be centered on the page. However, if you want a full page look this is easily achievable by omitting any content in either the main or the sidebar areas. The resulting area will be centered. See the Services page for an example of how this looks.
Each page also contains a "Lead" area that is as wide as both the main and the sidebar combined. It is centered. The Careers page has had all the content moved to the "Lead" area as a demonstration.