Question

1. identify the line of reflection. select = select x y

Explanation:

Step1: Observe the graph

Notice that for each point in triangle PQR and its corresponding point in triangle P'Q'R', the x - coordinate changes while the y - coordinate remains the same.

Step2: Recall reflection rules

A reflection over the y - axis changes the sign of the x - coordinate of a point while keeping the y - coordinate the same.

Answer:

$x = 0$ (or the y - axis)