Answer: The required similarity ratio is 1 : 10.
Step-by-step explanation: We are given to find the similarity ratio for the two circle with areas as follows:

Finding a similarity ratio for two circles is equivalent to finding the ratios of their radii.
Let,
and
be the radii of the two circles with areas
and
respectively.
So, we have
![(A_1)/(A_2)=(2\pi)/(200\pi)\\\\\\\Rightarrow (2\pi r_1^2)/(2\pi r_2^2)=(1)/(100)\\\\\\\Rightarrow (r_1^2)/(r_2^2)=(1)/(100)\\\\\\\Rightarrow (r_1)/(r_2)=(1)/(10)~~~~~\textup{[taking square root on both sides]}\\\\\\\Rightarrow r_1:r_2=1:10.](https://img.qammunity.org/2018/formulas/mathematics/high-school/tb83qpqj8n66r8c3e9p6op9r0ciy9wdjzs.png)
Thus, the required similarity ratio is 1 : 10.