The Primitives, Cylinder (Surface menu) image\cyl.gif command creates a single ruled surface between two arcs:

Primitives, Cylinder example

You are asked to digitise a centre point and a Radius, and then to drag the cylinder out to the specified endpoint (or specify a Length). The command takes the axis of the cylinder from the first and third points that you digitise.

To create a circular surface at each end of the cylinder, select the Closed option.