The relationship [tex](x,\;y)\rightarrow (y,\;x)[/tex] used by Calton to find the points of the image.
Given:
Clayton needs to reflect the triangle below across the line [tex]y=x[/tex].
According to the question, A triangle ABC which have to reflected by the point [tex](x,\;y)\rightarrow (y,\;x)[/tex] to get the image of the points.
In the most simple terms, the solution would be [tex]y=x[/tex] because of this line, which travels straight through the origin.
It is the only given line that passes through the center of the given reflection.
Now, the vertices of [tex]\Delta ABC[/tex] will be written as [tex]A\rightarrow A',\;B\rightarrow B'\;\&;\;C\rightarrow C'[/tex] and The image and the pre-image will be congruent triangles.
Therefore, Clayton could use the relationship [tex](x,\;y)\rightarrow (y,\;x)[/tex] to find the points of the image.
Learn more about the reflection of the graph here:
https://brainly.com/question/1873328