Unit Vec A Dot B = Cos Theta

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Math was one of my favorite subjects in school, thanks to great teachers. However, trigonometry's teaching method was confusing for me. This device helps students familiar with geometry and algebra visualize how cosine values in trigonometry can be computed using a unit vector dot product. If one vector is [1,0], the cosine is simply the x value. Check out this YouTube video for an explanation: http://youtu.be/AQ0t7twdW-M. In the example provided, with a 60° angle (π/3 radians), unit vectors A and B are [0.5, 0.866] and [1,0], respectively. Using the dot product formula Ax∙™Bx+Ay∙™By=Cos ø, the result is 0.5 due to By being zero. The same answer of 0.5 can be obtained by computing the dot product of another two points, A and B, that are 60° apart. Turning the dial π/3 radians (or 60°) results in the same value in the cosine plot. To recreate this device, print one each of the provided STL objects. I used multiple layer colors for Object #1 at specific points and two-colored layers for Object #4 at a particular height. Sand the channel and rails, clean them thoroughly, and apply synthetic PTFE grease in the channel. Finally, glue the parts together with super glue according to the instructions.