
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 that the three internal angles of triangle ABC are A, B, C, and $2\sin^{2}(B+C)= \sqrt {3}\sin2A$.
(I) Find the degree measure of A.
(II) If BC=7, AC=5, find the area S of triangle ABC.

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