
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 $C$: $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1(a>b>0)$ with eccentricity $\frac{2\sqrt{2}}{3}$, the line $y=\frac{1}{2}$ intersects $C$ at points $A$ and $B$, where $|AB|=3\sqrt{3}$.  
$(1)$ Find the equation of $C$;  
$(2)$ Let the left and right foci of $C$ be $F_{1}$ and $F_{2}$ respectively. The line passing through $F_{1}$ with a slope of $1$ intersects $C$ at points $G$ and $H$. Find the perimeter of $\triangle F_{2}GH$.

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