This pre-image has been reflected over the y-axis to form an identical image in quadrant one. To reflect any object, several rules need to be followed. The pre-image that is being reflected will always be reflected over a line. This line has to be equidistant from each of the corresponding points of the images. For example, point A has to be the exact same distance from the line as point A’. Also, the image has to be congruent to the pre-image or is an isometry. Using these properties, a reflection of a pre-image can be created.