1. The problem statement, all variables and given/known data Consider the parametrization of torus given by: x=x(ø,ß)=(3+cos(ø))cos(ß) y=y(ø,ß)=(3+cos(ø))sin(ß) z=z(ø,ß)=sin(ø), for 0≤ø,ß≤2π What is the radius of the circle that runs through the center of the tube, and what is the radius of the tube, measured from the central circle? 2. Relevant equations ? 3. The attempt at a solution Hmmmm..... I don't get it. The distance from a point on the torus to the center would be √(x2+y2+z2), I think. But the center of the tube? Not sure how that would work. H Help is appreciated. And after that, I may ask some more questions. I know you folks are ready, willing, and able.