Here is a quote from the first paper cited below: Steinhaus posed a version of your question, which has become known as [*simple polygonization*](http://erikdemaine.org/polygonization/) of a set of points: <hr /> [![Steinhaus][1]][1] <hr /> ><sup>1</sup>Agarwal, Pankaj K., Ferran Hurtado, Godfried T. Toussaint, and Joan Trias. "On polyhedra induced by point sets in space." *Discrete Applied Mathematics* 156, no. 1 (2008): 42-54. > <sup>25</sup>Hugo Steinhaus. *One Hundred Problems in Elementary Mathematics*. Dover Publications, Inc., New York, 194. Subsequently, Michael Gemignani removed the general-position assumption, relaxed to not-all-collinear. And then Grünbaum offered a simple proof that leads to an $O(n \log n)$ algorithm.<sup>1</sup> Fedor Petrov's solution is known as a *star polygonization*. Finding a minimal-area simple polygonization is NP-hard. [1]: https://i.sstatic.net/7bQoz.png