Click the Lat/Long button in the Project Limits and Scale dialog to open the Specify Lat/Long Limits dialog.
Type the limits for the project in latitude and longitude degrees.
Use this dialog to enter the project limits in latitude and longitude coordinates, instead of in display units. The values must be input in decimal degree format.
See Also
Latitude/Longitude Coordinates
Latitude/Longitude in Decimal Degrees
Using Scaling to Minimize Distortion in Latitude/Longitude Projects