KöMaL 2018 C1510

The base radii of a right circular truncated cone are $8$ cm and $5$ cm. The slant height is $12$ cm. If the truncated cone is laid on its side and rolled, it will trace out a circular ring in the plane. Determine the radii of the inner and outer circles of the ring, and find the number of times the truncated cone rotates about its axis while it rolls around and returns to its starting position.