In Google Docs on a computer, open File → Page setup and check that the document uses Pages. Select the text or image you want on the wide page, right-click it, and choose Change page to landscape. For more control over where the landscape portion starts and ends, put it in its own section.
01Select only the content that needs the wider page
Section linkFor example, select a wide chart and its caption without selecting the following paragraph. Use Change page to landscape from the right-click menu. Check the pages around the chart after Docs lays out the selection. The new layout can move nearby text, so check that the chart and caption are still together.
02Use section breaks for precise boundaries
Section linkClick just before the content you want to rotate and choose Insert → Break → Section break (next page). If more portrait content follows, insert another section break before that content. Click inside the section you want to rotate, then open Format → Page orientation. Under Apply to, choose This section, then select Landscape and confirm.
03If later pages also turn landscape
Section linkUndo the change and check that you used This section rather than This section forward or Whole document. Use View → Show section breaks to see whether a boundary separates the landscape content from what follows. If the section spans more than a page, the orientation applies to the whole section; shorten or split the section if needed.