I think sometimes a basic knowledge of trigometry can save you time and .. misery.

You could stand at a corner in your farm and take compass readings as well as GPS readings, then walk and reach point B and do the same for other corners or whatver stands out in your farm (house chimney , barn door ..etc.). Take a safe route at an angle and walk for a reasonable distanse and take GPS and compass readings for the other features.

You only take readings at safe points on TWO adjacent sides of the farm and do NOT have to go to the other side. When you are at home with nice cuppa coffee, you draw everything on a piece of paper and use your calculator to calculate the rest.

At least, that is what I would have done being the lazy coward that I am. he-he he-he he-he

And I would have done that daytime.