Similar to delaunay triangulation

given a set of 2d points, what delaunay function does is form a matrix TRI(m*3) and then triplot can be used to plot those triangles..

Now my question is: Given a set of 2d points , Can we form squares or quadrilaterals, that is first form say quad(m*4) matrix and then plot these squares...??

Any help will be hugely appreciated...