
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
Calculate the following sum:
\[\text{cis } 40^\circ + \text{cis } 50^\circ + \text{cis } 60^\circ + \dots + \text{cis } 140^\circ\]
and express in the form \(r \, \text{cis } \theta\), where \(r > 0\) and \(0^\circ \leq \theta < 360^\circ\). Find \(\theta\) in degrees.

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