
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 the area of $\triangle ABC$ is $S$, and $\overrightarrow {AB} \cdot \overrightarrow {AC} = S$.  
(I) Find the value of $\tan 2A$;  
(II) If $\cos C = \frac {3}{5}$, and $|\overrightarrow {AC} - \overrightarrow {AB}| = 2$, find the area of $\triangle ABC$ as $S$.

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