Abstract: In this study we propose a new Lightness Equilateral Triangle Localization Algorithm (LETLA) that accurately localizes sensors while minimizing power consumption and independent on any extra hardware. In the LETLA, which is based on geometric characteristics of equilateral triangle layout, anchors are placed in the vertexes of many equilateral triangles. The equilateral triangle that contains the located node is determined by examining the ordered sequence of ranging result taken at multiple anchor nodes and the intersection of two arcs is substituted by the intersection of two tangent lines which is the approximate location of located point in LETLA. Through extensive simulations, we show that LETLA performs better than other state of the art approaches in terms of energy consumption with the same localization precision.