Which type of transformation is shown?
Let’s say we start with the blue triangle. And after some transformation, we get the green triangle. Imagine that there was a line at 𝑦 equals four. If we could fold the graph at the line 𝑦 equals four, the green and blue triangles would line up perfectly.
If we look at the point six, zero, it is four units away from our yellow line. That same point in the green triangle is four units above the yellow line. Looking at another point that is one unit below the yellow line, its reflection is one unit above the yellow line. And our final point is on the yellow line. And that means a reflection over the yellow line wouldn’t change that point.
All of this information confirms for us that this is a reflection.