Let's begin with recalling the Side-Side-Side Congruence Postulate.
If three sides of one triangle
are congruent to three sides
of a second triangle, then the triangles
are congruent.
Now let's look at the given picture.
We are given that two corresponding sides are congruent, and we can see that the third side is common to both triangles. This means that three sides of one triangle are congruent to three sides of a second triangle. Therefore, it is possible to prove congruence in this case by the SSS Congruence Postulate.
