These are located on the toolbar at the top of the screen. Initially they will be "grayed out" (disabled) until you select a shape or shapes.
Flip the selected shape vertically.
Flip the selected shape horizontally.
Rotate the selected shape 90° clockwise.
Rotate the selected shape 90° anticlockwise.
Enter a number in the box and click the button to rotate the selected shape by the specified amount. A negative number will rotate anticlockwise.
The rotation is cumulative. This means the value in the box is added to any previous rotation.