Imagine wrapping an arc of length [math]b[/math] around a unit circle to create a central angle [math]\theta[/math] and a reference triangle.

Graphing [math](t, \cos(t),\sin(t))[/math]. [br][br]Imagine a ferris wheel traveling through time. Think of the green axis as the [math]t[/math]-axis, time, the red axis as the horizontal [math]x[/math]-axis, and the blue axis as the vertical [math]y[/math]-axis. [br][br]Rotate the 3-dimensional view to "hide" each of these axes, thereby showing how the other two quantities relate to each other.