Answer:
Two triangles are said to be congruent by ASA congrency criterion if the two angles and side between them are equal or congruent.
Refer to the image attached.
To prove:

Given:

Now, we can observe that the side AB is between the angles A and B and the side XY is between the angles X and Y.
Since it is given that
, so the condition
should be known to shows these triangles congruent.