Consider the two triangles. to prove that △lmn ~ △xyz by the sss similarity theorem using the information provided in the diagram, it would be enough additional information to know that lm is 3 units and xz is 5 units. lm is 4 units and xz is 6 units. lm is 5 units and xz is 3 units. lm is 6 units and xz is 4 units.