Answer: SAS similarity Theorem.
Explanation:
1) SAS stands for Side-Angle-Side
2) SAS Theorem postulates that when two sides of a triangle are proportional to two sides of other triangle and one angle of one triangle is congruent to one angle of other triangle then the two triangles are similar.
3) In this case you can verify the SAS theorem and conclude that the triangles are similar by:
3.1) proportionality of sides:
6 3
--- = ----
4 2
3.2) angle congruency
at point M the angles are opposite by the vertex, which means that the angles are congruent.
So, you have shown that the two triangles are similar in virtue of SAS Theorem.
