Created with GeoGebra |
The smaller circle, radius $r$, rolls around without slipping
inside the circumference of the larger circle, radius $2r$.
$P$ is a point on the circumference of the smaller circle . What is the locus of $P$? |
This dynamic image is drawn using Geogebra, free software and very easy to use. You can download your own copy of Geogebra from http://www.geogebra.org/cms/ together with a good help manual and Quickstart for beginners.