Question 554090
Recall that S = side, A = angle.


SAS congruency is a postulate that says that if two triangles have two congruent side lengths, and the angle between them is congruent, then the two triangles are congruent (e.g. if two triangles each have sides of 5 and 6 and the included angle is 57 degrees, then the triangles are congruent).


AAS and ASA are similar; if two triangles have two sets of congruent angles, and the corresponding sides are equal, then the two triangles are congruent.


SSS states that if two triangles have corresponding side lengths (e.g. two 3-4-5 triangles) then the triangles are congruent.


Note that these postulates can also be used to prove similarity.


http://en.wikipedia.org/wiki/Congruence_(geometry)