Draws sine wave from a circle, no trigonometry. Red pen matches the Y coordinate of a circling point. Pen moves forward on X axis. A sine wave pattern results. Used very little code and no trigonometry functions. The "X" in the lower left simulates pendulum by matching x position of circling point.
2nd pen moves forward the distance of the circle circumference traveled, 2 x pi when radius = 1. Notice motion of Y position slows down at ends and is fastest near 0, corresponding to a sine function (but we didn't use trigonometry). The same is true of motion of X, like a pendulum or spring motion. Contrast with my project using sine and cosine function: https://scratch.mit.edu/projects/600800374/ I did pretty much the same thing with no trig a few months ago: https://scratch.mit.edu/projects/500868935/ but this one here more clearly shows the relationships to the sine wave and pi.
