When you click a point, you may choose to chow its caption or value, or simply hide the label.
unit circle and symmetry
This set of 8 points on the unit circle demonstrate various relations among angles being symmetric about the axes or diagonal lines. [br][br]You can drag a point to change one marked angle and see how all other angles change while keeping certain relations. You may ask questions about how the x- and y- coordinates are related. As a result, you can figure out how the sine and cosine of these angles should be related. [br]