Answer:
C=6π
Step-by-step explanation:
It is given that, two circles are identical. The radius of first circle is 2x and the diameter of other circle is 2x+3.
If identical, it means that the radius of both circles are same i.e.

Radius of both circles is 2(1.5)=3
The circumference of a circle is given by :

So, the circumference of each circle is 6π.