title: SOCP relaxation in Euclidean geometry optimization For n points in the plane, suppose m of the points are known and the Euclidean distance between pairs of `neighboring' pts are known. We wish to estimate the remaining n-m points. Recently Biswas and Ye proposed an SDP relaxation for this problem in the context of ad hoc wireless sensor network localization. Here we consider SOCP and mixed SOCP-SDP relaxation for the problem and study the quality of the approximate solutions and methods for solving the relaxations.