Autocad: The fastest rotation of objects by 180 (90°,270°) degrees with one button (W)
The following conventions are used for the various angle measures:
Surveyor's units: N or S for north or south bearings, and E or W for east or west. If the angle is precisely north, south, east, or west, only the single letter representing the compass point is displayed.
Just press one button "w" and it will replace 180
180-W
270-N
90-E