[RicoElectrico]

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).

[lapetitejort]

tan(x)~x because cos(x)~1. It's approximations all the way down.