How to Change Page Size
in Google Docs

Open your Google Docs document.

Click on the "File" menu at the top, then select "Page setup".

In the "Page setup" window, you can adjust the page size by selecting from preset options like "Letter", "A4", or by entering custom dimensions in the "Custom" option.

If you want to apply the changes to the entire document, click "OK".

If you want to apply the changes to only a specific section, select "Apply to this section" before clicking "OK".