To rotate objects first select them.
You can quickly rotate them by pressing the Space bar.
You can also rotate them using any of the commands in Edit→Rotate ribbon button group.
Click the 
button to rotate the selected objects clockwise by 90°.
Click the 
button to rotate the selected objects by 180°.
Click the 
button to rotate the selected objects anticlockwise by 90°.
To rotate selected objects by a set angle, enter the angle in the 
control and click the 
button.
You can also scale objects by dragging the rotate 
handles.
Selected box showing scale and rotate handles.