How do you rotate a pdf document in preview?

There is a book where the double pages are turned. How do you rotate them so that you can read them in preview?

There are three ways.
1. If you have a toolbar on your page (opened by clicking the gray oval in the upper right hand corner) you should see the 'Rotate' option there (it's blue).
2. Click Tools in the Menu Bar. Rotate left and Rotate right are there.
3. Command L for Left, Command R for right.
Rotate until they face the right way. You should be able to save the changes in orientation.