## Trigonometry (11th Edition) Clone

Arc length s (radius r, central angle $\theta$):$\quad s=r\theta$, where $\theta$ is in radians ---------------- Before the radius increases, $s_{1}=r\theta$. After $r$ increases to $2r$ (and the central angle remains the same), $s_{2}=(2r)\theta=2(r\theta)=2s_{1}$ The arc length doubles.