Because the circle is such a simple curve, it has hardly made an appearance on these pages. However, there is some interest in the pedal curves of the circle.




Click the linked diagram below, and then click the ‘Animate’ button to generate the pedal curve of the circle with respect to the point Q. Clicking the little red x which appears at bottom right will clear the drawing from the applet window. Can you describe the construction? Experiment with different positions of the point Q. Of special interest is when Q lies on the circle. What happens when Q lies at the centre of the circle?