
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Two concentric circles have radii of 10 and 20 units, respectively, and bound a shaded region. A third circle is to be drawn such that its area is equal to that of the shaded area. Additionally, calculate the circumference of this third circle.

Present the answer in LaTex format: \boxed{Your answer}
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