Rolling simplexes and their commensurability (laws of mechanics as a problem of choice between metrics and measure)

It can hardly be determined who noticed that Newton's first law could be interpreted as Kepler's second law for any observer, located out of the line trajectory of a freely moving body, and hammered the nail into the lit for metrics. However, every next generation, paying no attention to “Golden Rule of Mechanics” and “Lever Rule,” with perseverance worthy of better cause has extracted it from the grave. In this paper, we bring forward additional (and forcible, from our standpoint) arguments in direction that we should always study the original measure of things, in particular, we think that setsquare can be most advantageously substituted for compasses at a certain stage of teaching plane geometry at school.