For single-page actions, the Pages pane
Pages pane > On the desired page click More ('...') > Select your desired function
For multi-page actions, the More "..." pane
More "..." pane > Page Manipulation >
For multi-page actions, the 'View all pages' button
View all pages > Edit document > Select pages > Rotate/duplicate/delete
Note: Annotations will 'auto-rotate' along with a page's original orientation, if you discover your annotations 'flipping' undesirably, create a new page with the intended orientation before using it.