Multisided tower

[cslatteryAXGRE]

We are looking to create a tower that has multiple sides, like a polygon. It could have 8, 10 or 12 sides, and different diameters at the top and bottom. I started out with an adaptive family, creating a polygon that can be edited from the instance properties, but I do not know how to create a form out of this. has anyone ever done this before.

[ToanDN]

Start from a Conceptual Mass family, not Adaptive family.

[cslatteryAXGRE]

Thanks. 

I am trying the conceptual mass, I am still not understanding how to do this. I placed two points, then a circle, then i divided my circle, then I added a line I made in an adaptive family and stretched it between two points, then rotated it so it made a polygon. I am unable to create a form because I have no lines. If I add lines then i cannot change the number of sides.