There are 4 ways to rotate the image currently being viewed.
1.Rotate an image 90° by clicking either the rotate left 
or the 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 select 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 Image Commands 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.