| Applet starten |
Imagine a circle O and a grid consisting of horizontal lines and vertical lines. The inverse of each line in O is a circle, so, if you start with 18 lines, then you'd also have 18 circles. Now, imagine hiding the 18 lines, but keeping the circles, and then rotating the center of O around the origin of the grid. To start or stop the motion, click the Animate Point button.
Can you figure out the role played by each of the red points?