
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 an ellipse $\dfrac{x^{2}}{a^{2}}+ \dfrac{y^{2}}{25}=1$ $(a > 5)$, its two foci are $F_1$ and $F_2$, and $|F_1F_2|=8$. Determine the perimeter of $\triangle ABF_2$ given that chord $AB$ passes through focus $F_1$.

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