I was thinking about making $\sqrt 3$ by folding (for example $A4$ paper). I do $\sqrt 2$ as a simple folding like below :
Remark: It is easy to make $\sqrt2 , \sqrt5$ by folding by $1:1$ and $2:1$ ratio.
But I got stuck on making $\sqrt3$ somewhat similar to that way or making some easy folding, Or using Theodorus spiral in folding.