Reflection of light — Use

How can ray diagrams and measurements be used to find the position and size of an image formed in a plane mirror?

Draw the object and mirror to scale, then from a point on the object draw two incident rays to the mirror and apply the law of reflection (angle of incidence = angle of reflection, measured from the normal) to draw the reflected rays. Extending the reflected rays backwards as dashed construction lines behind the mirror locates the virtual image at the point where they appear to meet; measurement confirms the image distance behind the mirror equals the object distance in front.