&= \dfrac{r^2 \theta}{2}
\end{align*}
- \[ \textbf{Segments: } A = \dfrac{r^2}{2} \left( \theta = \sin \theta \right) \]
+ \[ \textbf{Segments: } A = \dfrac{r^2}{2} \left(\theta - \sin \theta \right) \]
\begin{align*}
\textbf{Chords: } \operatorname{crd} \theta &= \sqrt{(1 - \cos\theta)^2 + \sin^2 \theta} \\