Chapter 3 - Radian Measure and the Unit Circle - Section 3.2 Applications of Radian Measure - 3.2 Exercises - Page 110: 5

$1$ radians

Step 1: The formula to be used here is $s=r\theta$ where s is the length of the arc intercepted, r is the radius and $\theta$ is the central angle of measure in radians. Step 2: $s=r\theta$ Step 3: $3=(3)(\theta)$ Step 4: $\theta=1$ radians