To Rotate an Object to an Absolute Angle

Click Home tabModify panelRotate. Find
Select the objects to rotate.
Specify the base point for the rotation.
Enter r (Reference).
Enter a reference angle value or specify two point locations.
This determines an imaginary line that will be rotated to a new angle.
Enter the new angle, or specify a point.
The value that you enter for the new angle is an absolute angle, not a relative value. Alternatively, if you specify a point, the reference angle will be rotated to that point.