to this:
... having calculated everything, starts folding on the calculator - 20 + 20 + 20 +... and so on. I say, well, you have 9 times, 20 times, and 180 times. Surprise in empty eyes. The Magic!
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I worked 15 years ago as a student at the "euroremont", it was necessary to level the hall 20 by 20 meters, the angles to be straight between the walls well and so on... and the "angle" we had only a meter per meter, the error of 20 meters was huge.

This is where the knowledge of the Egyptian triangle was useful... the benefit of the rope was at least to repel. Hypothenus 20 meters made) here the brigadier walked on foot when his walls joined millimeter by millimeter)