Answer:
![C'=24\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/qvaski5r8exmbl2nvs7n5skwemz13ktw44.png)
Explanation:
we know that
Since all circles are similar to each other
The ratio of the circumferences of two circles is equal to the scale factor
The ratio of the diameters of two circles is equal to the scale factor
so
The ratio of the circumferences of two circles is equal to the ratio of its diameter
therefore
![(C)/(C')=(d)/(d')](https://img.qammunity.org/2020/formulas/mathematics/high-school/c9gppsnzp00b6wq805j5l7qend18dbn64g.png)
we have
![C=6\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/8djki9fdk9qs5eeqizkziryjyo03auq833.png)
substitute
![(6)/(C')=0.25](https://img.qammunity.org/2020/formulas/mathematics/high-school/lddft733htw3xwnmgfqela4u83f3kcpl9l.png)
![C'=(6)/(0.25)=24\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/so9bv5fb6i3wx01nt26x7r6ak7tfr7xhcg.png)