Come on, at this point I've seen this "engineering approximation" memed so many times, even on Instagram ;) What is more interesting to me is that this can be

Come on, at this point I've seen this "engineering approximation" memed so many times, even on Instagram ;) What is more interesting to me is that this can be one of rationales behind using radians. And that tan(x)~x also holds for small angles, greatly easing estimations of distance to objects of known size (cf. mil-dot reticle).