It's also possible with Resize to force pages to a consistent size. This is used a lot for proposal books. They typically need 2 page size: Letter/A4 Portrait pages and Ledger/A3 Landscape (for engineering folds)
You would use resize any page that is "almost" or "fits into" a size a little bigger than Letter/A4 to exactly Letter/A4. Then Rotate to make any landscape Letter/A4 page into Portrait.
Any pages larger than the "little bigger" value would be resized and rotated to Ledger/A3 landscape.
very useful to make all pages, including CAD drawings to be uniform orientation and size.