Final answer:
Yes, the two squares are congruent because the reflection and translation operations preserve their length of sides, orientation, and position relative to the y-axis.
Step-by-step explanation:
When a square is reflected across the y-axis, its x-coordinates are negated without affecting the y-coordinates. This means that the new square will have the same length of sides as the original square, but will be on the opposite side of the y-axis.
When the reflected square is translated 3 units down, both the x and y-coordinates are shifted by 3 units in the downward direction. This means that the new square will have the same length of sides, same orientation, and will be located 3 units down from the original square.
Since the new square has the same length of sides, orientation, and position relative to the y-axis as the original square, they are congruent.