Consider the torus of revolution generated by rotating the circle (x − a)² + z² = r², y = 0, - about the z axis (a > r > 0). The parallels generated by the points (a +r, 0), (a −r, 0), (a, r) are called the maximum parallel, the mini- mum parallel, and the upper parallel, respectively. Check which of these parallels is a. A geodesic. b. An asymptotic curve. c. A line of curvature.

The line joining two points A(2,0) and B(3,1) is rotated about A in anticlockwise direction through an angle of 15°. Find the equation of the line in the new position. If B goes to C in the new position,what will be the coordinates of C?