If an object is conveniently located in front of two plane mirrors placed at an angle, an observer can see a superposition of images that results in a face with three eyes, called in this text a "triclops." The conditions of occurrence of such an image may seem trivial, but this is incorrect: rather, the correct interpretation of this…

Utilizes vector mathematics to explain the reflective properties of a corner cube retroreflector, consisting of three plane mirrors assembled at right angles with a common vertex. Analyzes the useful property that an incident beam of light at any point in this reflector will return on a parallel path. (MDH)

Discusses solutions to the problem of maximizing the range of a projectile. Presents three references that solve the problem with and without the use of calculus. Offers a fourth solution suitable for introductory physics courses that relies more on trigonometry and the geometry of the problem. (MDH)

Describes an activity to study the concepts of force and gravity. Students use trigonometry to measure the height of a water balloon shot into the air by a giant slingshot by two methods. A lesson plan provides materials needed, procedures, a chart to record data, and extensions for the activity. (MDH)