
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
Let $P$ be a point on the ellipse $\frac{x^2}{25} + \frac{y^2}{9} = 1$, and $F_1$ and $F_2$ are the left and right foci of the ellipse, respectively. Draw a line through point $P$ perpendicular to the line through $F_1$ and $F_2$ at $H$. If $PF_1$ is perpendicular to $PF_2$, then find the length of $|PH|$.

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