$$\begin{aligned}\text{Area of sector} &= \dfrac{\theta}{360^\circ} \times \pi r^2 && \textcolor{gray}{(\theta \text{ in degrees})} \\ &= \dfrac{\theta}{2\pi} \times \pi r^2 && \textcolor{gray}{(\theta \text{ in radians})} \\ &= \dfrac{1}{2}r^2\theta && \textcolor{gray}{(\theta \text{ in radians})}\end{aligned}$$

$$\begin{aligned}\text{Arc length} &= \dfrac{\theta}{360^\circ} \times 2\pi r && \textcolor{gray}{(\theta \text{ in degrees})} \\ &= \dfrac{\theta}{2\pi} \times 2\pi r && \textcolor{gray}{(\theta \text{ in radians})} \\ &= r\theta && \textcolor{gray}{(\theta \text{ in radians})}\end{aligned}$$