Answer: The correct option is 1, i.e., SSS.
Step-by-step explanation:
It is given that in triangle ABC the line CM bisects AB. The side AC=BC. In triangle ACM and BCM,
AM = BM (CM bisects AB)
CM=CM (common side)
AC= BC (given)
Since three sides of triangles are equal.
According to SSS rule of congruence theorem, two triangles are congruent if all the corresponding sides of the triangles are equal.
So by SSS rule of congruence theorem, we can conclude that the triangles ACM and BCM are congruent.
The correct option is first, i.e., SSS rule.