Like any other text editor, Google Docs allows you to freely choose the format. If you want a document to be displayed in landscape format instead of portrait, you can set it up in advance.
Go to docs.google.com, log in with your user account and create a new document. Click on File/Settings, select landscape format under Format, and OK the change. And in the Apply to next drop-down list, you can choose whether the format should apply to the whole document or only to the selected content.