Point C is relected about the red line to obtain C'. The blue lines are the x-axis, y-axis and the y = x line.
Move the red line, by using the red point on the line, and move Point C to investigate how the points' coordinates relate to eachother. Can you figure out the coordinates of Point C' if you were given the coordinates of Point C and told if it was reflected over the x-axis, y-axis or the y = x line?