Click flag. See how a pendulum swing and sine wave correspond to a circle. Draws a circle just by turning a constant angle. Another pen matches the y coordinate of the circle but moves forward along the x axis. A pendulum simply matches the x coordinate of the circle. No trigonometry necessary.
Part of our box on pendulums and heavenly harmony. See also our orbit, based on the same idea: https://scratch.mit.edu/projects/502671708 https://scratch.mit.edu/projects/502435622/
