Connect shapes

Hi everyone!

I have a doubt and I need some help. Did anyone knows how could I do any shape (rectangle, square, polygon, etc.) and connect their edges so if one becomes bigger the next to it becomes smaller?

First I think that I have to create 2 or more shapes and limit their sizes with sliders (I don't know how, please help) And then connect their edges.
I don't know how easy or complicate it is but if anyone have an idea I will appreciate.

I have been looking for examples and neither find them.

Thank you and have a nice day.