Answer :
The line of reflection between the two pentagons is the y-axis.
We can see this because all of the points in pentagon P'Q'R'S'T' have the same x-coordinate as their corresponding points in pentagon PQRST, but their y-coordinates are negated. For example, point P has coordinates (-4, 6), and its reflected image P' has coordinates (-4, -6).
The y-axis is the only line that passes through all of the midpoints of the segments connecting corresponding points in the two pentagons. Since reflection preserves distance, the line of reflection must be the perpendicular bisector of any segment connecting a point in one pentagon to its reflected image in the other pentagon.
