Why do lots of formula's / equations have

I've been looking at many formula's both in mathematics and physics, this applies right across the board and I'm just wondering why soooo many of them have something or other squared. Why always squared and not cubed or something else? What is the nature for squaring something all the time?

Take for example

I just seem to notice that in every single math topic I start learning there is always some key formula or something that involves squares. Hardly ever do I see cubes or greater. Just wondering why...

Re: Why do lots of formula's / equations have

You can write your formula (the boost) in terms of an hyperbolic angle, getting rid of the square root, if you feel more comfortable or prefer a geometric interpretation of boosts as rotations. You can see a fourth law in Stefan-Boltzmann law for example..

Re: Why do lots of formula's / equations have

In classical mechanics (and indirectly in the Lorentz factor) the square is due to integration of a linear function. Maybe a similar reason explains other contexts?