
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
In the rectangular coordinate system $(xOy)$, the parametric equation of line $l$ is given by $ \begin{cases} x=t\cos \frac {2π}{3} \\ y=4+t\sin \frac {2π}{3} \end{cases} (t\text{ is a parameter})$, and the polar coordinate equation of curve $C$ with the coordinate origin as the pole and the positive semi-axis of $x$ as the polar axis is $ρ=4$.

1. Write the ordinary equation of line $l$ and the rectangular coordinate equation of curve $C$;
2. Line $l$ and curve $C$ intersect at points $A$ and $B$. Calculate the value of $∠AOB$.

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