Are triangles DEF and LNM similar if LN equals 4, MN equals 3, DE equals 12, and FE equals 9? Yes, by the SAS Similarity Postulate Yes, by the SSS Similarity Postulate No, the corresponding sides are not proportional No, there is not enough info
12:4 and 9:3 are the same ratio so the sides are proportional. Since they have a congruent angle too, the answer is yes by the SAS Similarity Postulate.
