\begin{definition}[Definition:Polar Coordinates/Angular Coordinate]
Let $P$ be a point in a system of polar coordinates where $O$ is the pole.
The angle measured anticlockwise from the polar axis to $OP$ is called the '''angular coordinate''' of $P$, and usually labelled $\theta$.
If the angle is measured clockwise from the polar axis to $OP$, its value is considered negative.
\end{definition}