Math explained in easy language, plus puzzles, games, quizzes, worksheets and a forum. For K kids, teachers and Rotation Game. Make the big circle. Because the angle is rotating around and around the circle the Sine, Cosine and Tangent functions repeat once every full rotation (see Amplitude, Period, Phase. Reflection Symmetry. The simplest symmetry is Reflection Symmetry (sometimes called Line Symmetry or Mirror Symmetry). It is easy to see, because one half is.