
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
A circular piece of paper has a radius 15 cm. Sarah cuts and removes part of this circle as shown in a diagram, then forms a cone by joining two edges of the remaining sector. The cone has a radius of 10 cm and a volume of $500\pi$ cm³. What is the angle measure, in degrees, of the sector Sarah removed?

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