How to know the interior area of the surface in revolution/Como saber el area interior de la superficie en revolución

[superministromax]

English: Hello, I have modeled an element in Revit, in this case I have modeled it as an in situ model, a generic model with a revolve as can be seen in the image. What I need is to be able to know the area of this surface on its inner face, and if it is possible to make this value be displayed in the properties of the family in situ in the same way that the area is displayed. Note: 1-What interests me the most is knowing the value with Revit and the one that is displayed in the properties is secondary.

Español: Hola he modelado un elemento en Revit, en este caso lo he modelado como modelo in situ, modelo generico con una revolucion somo se puede ver en la imagen. Lo que necesito es poder saber el area de esta superficie el su cara interior, y si es posible hacer qu este valor se visualize an las propiedades del la familia in situ al igual que se muestra el area. Nota: 1-Lo que mas me interesa es saber el valor con Revit y el que se visualize en las propiedades es secundario.

[alfmedina · Accepted solution]

Make that object as a family. In the family editor, use the Paint tool to paint the inner surface with one material ("poche", light green, in my example), and then paint the outer surface with another material ("default", gray). Then load the family into a project. Make a take-off schedule (Views > Schedule > Material take-off). Include "Material : name" and "Material : area" in the schedule. 

[constantin.stroescu]

for such cases I use  Dynamo  :

[superministromax]

Thank you. The answer helped me perfectly.

[superministromax]

Thank you. The answer helped me perfectly.