The Page Tool

The Page Tool

To resize pages with content proportionally, you first need to make sure the Adjust Layout option is enabled by going to Layout > Margins and Columns. This way your content will scale proportionally with the new page size. Then select the pages you want to resize via the Pages panel and select the Page Tool.

Liquid Page Rule

Liquid Page Rule

Next under the Liquid Page Rule (in the Control panel), make sure Scale is selected from the dropdown. Now enter your desired document dimension in the Control panel at the top, or select it from the dropdown menu e.g. Letter - Half. The (selected) pages should now resize proportionally with content and everything to the new dimension. The Page tool also lets you resize a page manually using the page handles you see around the border of the page. Dragging these around only gives you a preview. However, holding down Option/Alt will resize the page permanently.