[wdfifteen]

Originally Posted by jyl

But - the edge of the large coin is not a line segment. It is a circular arc that makes a full 360 degree loop. Thus the small coin makes 1 full rotation just to follow this arc. Even if the small coin were slid around the large coin's edge (the same point on the small coin's edge is always touching the large coin), it would make 1 full rotation by the time it returned to its original location.

3 + 1 = 4. The small coin makes 4 full rotations around its own center.

Arggghhh!! You baxtard!