Calculates the rolled length of a roll of material when the outside diameter of the material, thickness
of the material, and the diameter of the hole in the center or the tube on which the material is wound
are given. Variations due to stretching or softness of the material are to be ignored. An example
of rolled material would be a rolled carpet or a rolled sheet of paper from the paper mill. The length units that
can be used are yard, feet, inch, meter, centimeter, millimeter and mil. A mil is equal to one thousandth of an inch.
The initial units used in the table can be changed to any of the choices given.