The Ray Diagrams for Plane Mirrors Video Tutorial explains what a ray diagram is and demonstrates how to construct a ray diagram for a point object and an arrow object. Examples and applications of ray diagrams are discussed. The video lesson answers the following question: Plane Mirrors. Drawing a ray diagram is fairly simple for a plane mirror. Firstly we should draw an incoming ray: Figure 1: A diagram showing a ray incident on a plane mirror from an object. Notice that the object is clearly labelled and the direction of travel is indicated with an arrow on the ray. How to draw a ray diagram that shows the formation of a virtual image in a plane mirror. How to draw a ray diagram that shows the formation of a virtual image in a plane mirror. Ray diagram plane mirror