When adding a rig, it is important to made it in the front or back view. This first screenshot shows my first attempt, but I was then told when making a joint which will only bend one way, it is better to have the joints angled and not in a perfectly straight line. This would make the bend smoother (hopefully!)
To do the rest of the rigging, it is easier to do it in the perspective view.
To Attach the rig to the polygon, you first select the rig and then shift select the mo
Above you can see the joints have changed colour, showing the hierarchy and that the rig is now attached to the flag pole.
This proves that it has been skinned (attached), as the flag pole bends with the rig. It is maintaining the volume, as you can see bulging, but also dents and pinching by the bend.