1. Insert textbox or shape. 2. Select inserted object. 3. Right-click, choose "Position and Size" 4. Choose "Rotation" tab. 5. Click on Help.
Seth Chaiklin committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/b16f95724b69db8bd3327c36c26dd556d81c9c46 tdf#137133 update control names on Rotation help page