There are 4 ways to rotate the image currently being viewed.
1.Rotate an image 90° by clicking on the rotate left 
and rotate right 
icons located on the toolbar.
2.Keyboard shortcuts:
• Clicking ] key rotates the image 90° degrees to the right.
•Clicking [ key rotates the image 90° degrees to the left.
3.Right click on the image and choose Rotate from the menu.
• 90° Right – rotates the image 90° to the right.
• 90° Left – rotates the image 90° to the left.
• 180° – rotates the image 180°.
4.Click the Image Commands button located on the Image Tab.
• Rotate Left – rotates the image 90° to the left.
• Rotate Right – rotates the image 90° to the right.
• Flip – turns the current image upside down and backwards.
• Reverse - changes the current image to a “mirror image” of the original.