After you click on Tools, click on the small down-arrow on the top of the column. That opens up a dialog that lets you select tools that aren't “on” by default, including Document Processing.
That having been said, none of the available Acrobat tools allow arbitrary page rotation. The Rotate Pages tool (under Pages tool) only offers rotations in 90 degree increments. The deskewing feature of the Optimize Scanned PDF tool doesn't provide for arbitrary page rotation, simply fixup of orientation of scanned text (i.e., text in images).
There are some third party Acrobat plug-ins such as Quite Software's Quite a Box of Tricks that can do arbitrary rotation of all objects within a page, modifying the page size if necessary (all pages are either portrait or landscape orientation).
- Dov