A ruled surface is one that can be generated by the movement of a straight line. The straight line in motion, in any of its positions, is called the surface generatrix. A ruled surface is generated by a straight line that moves in such a way that it always remains parallel to the XZ plane and cuts to the line z = 2, x = 0 and the circumference {2 Cos[t], 2 Sin[t], 0}.
