In order to change the page orientation in Word 2013 for one page only you have to use Section Breaks. First you should enable Paragraph marks and other hidden formatting symbols to be easier to work in your document
No go to the last page you want to keep current page orientation (usually the default orientation for all documents is Portrait) and select PAGE LAYOUT tab and click on Breaks > Next Page
Once the Section Break (Next Page) is added go to the end of the page you want to change the orientation, in this case Landscape, and add another Section Break (Next Page) . Go to PAGE LAYOUT tab and select Orientation > Landscape
Same steps apply for previous version of Word: 2010 and 2007.