
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 $$\begin{cases} x=- \frac {3}{5}t+2 \\ y= \frac {4}{5}t\end{cases}$$ ($t$ is the parameter). Establish a polar coordinate system with the origin $O$ as the pole and the positive semi-axis of the $x$-axis as the polar axis. The polar equation of circle $C$ is $\rho=a\sin\theta$. The chord length intercepted by line $l$ on circle $C$ is equal to $\sqrt {3}$ times the radius length of circle $C$. Find the value of $a$.

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