## Precalculus (6th Edition) Blitzer

The rectangular equation is, $y=4$
Using, $r\sin \theta =y$, we will convert the polar equation to the rectangular equation. Therefore, \begin{align} & r=4\csc \theta \\ & r=\frac{4}{\sin \theta } \\ & r\sin \theta =4 \\ & y=4 \end{align}