Reflection and Mirrors - Mission RM3 Detailed Help

An 'arrow object' is positioned in front of a plane mirror as shown. Along which line of sight must the eye look in order to see the topmost part of the image (i.e., the arrowhead)?


The diagram shows an object (labeled), the corresponding image (labeled), a mirror (vertical line with yellow backing), an eye position and five different lines of sight. Each line of sight is labeled with a letter. You are to determine which is the proper line that a person must sight along when positioned at the eye location in order to view topmost part of the image.

Line of Sight
Line of sight - it is a simple idea, but a very powerful idea once you get a grasp of it. To see anything, you must sight at the thing. To see an image, you must sight at the image. When you sight at the thing - whether the image or some other object - light from the thing travels along a line to your eye. Your eye and the thing you are looking at are two points on the line of sight along which you are looking.

As discussed in the Know the Law section, a person must sight at the image location in order to see the image. And when a person does sight at the image location, light will travel along that line of sight to the person's eye. In this question, it is desired that the person be able to view the topmost part of the image. Thus, the person must sight along a line towards the topmost part of the image. Since the image is shown, it is now a straightforward task to determine which line of sight is directed from the eye position toward the topmost part of the image.


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