We can see in this image that the triangle A'B'C' is a reflection of the triangle ABC over the line y = x (dashed red line, where each point has the same x and y coordinates).
In order to find the coordinates of the reflected points over this line, we just need to switch the x and y coordinates of the points:
[tex]\begin{gathered} A(-4,-2)\to A^{\prime}(-2,-4) \\ B(-2,0)\to B^{\prime}(0,-2) \\ C(-5,1)\to C^{\prime}(1,-5) \end{gathered}[/tex]
