Unit Circle shows the relationship between angles and trigonometric functions like sine and cosine. To do this, the program implements an interactive "unit circle" (radius = 1) diagram, where the user can click or drag to set angles and see how the values of trigonometric functions change accordingly.The unit circle (where the radius equals 1) provides a very clear demonstration of how various trigonometric functions relate to angles and one another. Draw an angle line from the origin to a point on the circumphrence of the circle; the (x,y) coordinates of that point will will be the cosine and sine of the angle.
In Unit Circle, use the mouse to set the angle line by either clicking or dragging the pointer inside the diagram. Or, change the trigonmetric values in the fields, and the angle will automatically adjust.
The inspiration for this program was provided by my home-schooled daughters, who had difficulty understanding the nature of trigonometry. As an educational tool, Unit Circle has been a success, and it may evolve into a larger application for exploring other aspects of trigonometry and geometry.