A cylindrical container has height 6cm and radius 4cm. It rests on a circular hoop, also of radius 4cm, fixed in a horizontal plane with its axis vertical and with each circular rim of the cylinder touching the hoop at two points.
The cylinder is now moved so that each of its circular rims still touches the hoop in two points. Find with proof the locus of one of the cylinder’s vertical ends. geometry unsolvedgeometry