Calculating Trigonometric Functions by Points

$$ \begin{matrix} \sin\theta = \frac{y}{r} & \qquad\cos\theta = \frac{x}{r} & \qquad\tan\theta = \frac{y}{x} \\ \sec\theta = \frac{r}{x} & \qquad\csc\theta = \frac{r}{y} & \qquad\cot\theta = \frac{x}{y} \\ \end{matrix} $$