
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
Given space vectors $\overrightarrow{a}$, $\overrightarrow{b}$, $\overrightarrow{c}$ satisfy $\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}=\overrightarrow{0}$, $|\overrightarrow{a}|=1$, $|\overrightarrow{b}|=2$, $|\overrightarrow{c}|=\sqrt{7}$, then the angle between vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ is ______.

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