1. The problem is to find the length of an arc of a circle. 2. The formula for the length of an arc $L$ is: $$L = r \theta$$ where $r$ is the radius of the circle and $\theta$ is the central angle in radians. 3. Important rules: - The angle $\theta$ must be in radians. If given in degrees, convert it using: $$\theta_{radians} = \theta_{degrees} \times \frac{\pi}{180}$$ - The radius $r$ is the distance from the center of the circle to any point on the circle. 4. To find the arc length: - Identify the radius $r$. - Convert the central angle to radians if necessary. - Substitute values into the formula $L = r \theta$. - Calculate the product to get the arc length. 5. Without specific values for $r$ and $\theta$, the arc length formula remains as: $$L = r \theta$$ This formula allows you to calculate the arc length once you know the radius and the central angle in radians.