You can choose either portrait (vertical) or landscape (horizontal) orientation for all or part of your document. When you change the orientation, the galleries of predesigned page and cover page options also change to offer pages that have the orientation that you choose.
What do you want to do?
Change the orientation of your entire document
On the Page Layout tab, in the Page Setup group, click Orientation.
Click Portrait or Landscape.
Use portrait and landscape orientation in the same document
Select the pages or paragraphs that you want to change to portrait or landscape orientation.
Note: If you select some but not all of the text on a page to change to portrait or landscape orientation, Word places the selected text on its own page, and the surrounding text on separate pages.
On the Page Layout tab, in the Page Setup group, click Margins.
Click Custom Margins.
On the Margins tab, click Portrait or Landscape.
In the Apply to list, click Selected text..
Note: Microsoft Word automatically inserts section breaks before and after the text that has the new page orientation. If your document is already divided into sections, you can click in a section (or select multiple sections), and then change the orientation for only the sections that you select.