Got hung up and could not move. How did I get out?

I did some calculations together with AutoCAD drawings to simulate my MH going up a steep driveway. I can safely go up a 8.7 degree slope (A radius of 106' passes tangent to front wheels, rear wheels, and rear hitch) without dragging the rear hitch. That equates to a 8' long 2x4 centered over the toe of the incline with a 1" gap below, that I can measure if necessary.

It was a slow afternoon at the office.