In this paper a new algorithm for recognizing 2D objects is introduced. The proposed algorithm is based on searching for first three matched connected lines in both input and model objects, then left and right lines in both input and model objects are marked as matched lines as long as they have the same relations of distance ratio and angle to the last matched and connected lines. The process is repeated until there is no more three matched connected lines. The ratio_test is then performed to detect scattered matched points and lines. The new algorithm is invariant to translations, rotations, reflections and scale changes and has O(m.n) as its computational complexity.