How to change the page layout from Portrait to Landscape in OpenOffice?
You can change it from Portrait to Lanscape using the Styles and Formatting Window (or press F11). Click on the Page Styles icon. Select Landscape from the list. In case it does not appear, the Default might be selected. Right click on Default and then select New. Choose the Page tab and change the page orientation to Lanscape using the radio button. Click Ok and the Style will appear in the page style selection menu. Select Landscape and that’s it.
For more information, access the website that deals with this question: https://wiki.openoffice.org/wiki/Documentation/FAQ/Writer/FormattingPagesAndDocuments/How_do_I_change_the_page_layout_from_Portrait_to_Landscape_for_an_entire_document%3F