Intersection of Surfaces

Hello Everyone,
The width of these 3 surfaces around the interior rectangles is 1.2.
How can I find the intersection of these three surfaces, such that the distance between the interior rectangles always remains 1.2?
I want to work on the optimization of the total area of the surface left between the interior rectangles.
The fitness function is the area of the inbetween surface that I mentioned.
I will be so thankful if you guide me.

mine is just a wild guess, but I think I would first draw a fixed rectangle (A) then create its offset

then build a second rectangle (B) on a point along the offset just created, and also offset that

then build a 3rd rectangle (C or C’) starting from one the two intersection points of the previous offset curves

the intersection area you show in figure should be the union of the intersections of any two offsets?

Thank you so much for your response.
I add this part to the algorithm too. To keep the distance between central points minimum. This should be my first logic which I think it has some mistakes.

Thank you so much for your response.
Yes that is right the intersection area I mean is the intersections of any two offsets that you colored black.
I assume that I have to write a logic algorithm. To tell Galapagos, considering the distance of minimum1.2 between two interior rectangles, if two interior rectangles collide, the solution is FALSE and should not go to the next step by the genetic algorithm.
Don’t you think this is a good solution? Actually, I don’t know how to write the logic.