Parametrization of a boundary of a closed disk

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The question that I am referring to is:

Let $D$ be the closed disc bounded by the circle with equation

$$(x-6)^{2} + y^{2} = 36$$

I am asked to find the parameterization of the boundary.

I am a bit confused on how to do this. I know that $x^2 + y^2 = 36$ which means $r = 6$.

Since $x = r\cos(\theta)$ and $y = r\sin(\theta)$, how would the $(x-6)^2$ be parameterized?

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HINT

In general, if we are given the circumference \begin{align*} (x-a)^{2} + (y-b)^{2} = r^{2} \end{align*}

we can parametrize it as follows

\begin{align*} \begin{cases} x = a + r\cos(\theta)\\\\ y = b + r\sin(\theta) \end{cases} \end{align*}

where $\theta\in[0,2\pi]$. Can you apply it to the example proposed?