Answer:
5 rad
Step-by-step explanation:
Recall that the length of an arc of circumference is given by the formula:
[tex]Arc\,Length=\theta\,*\,radius[/tex], where [tex]\theta[/tex] is the subtended angle [in radians] from the circumference's center.
Therefore in this case, you know the arc length (81.5 cm), and the radius (16.3 cm), and can solve for the angle [tex]\theta[/tex] using the above equation as shown below:
[tex]Arc\,Length=\theta\,*\,radius\\81.5\,cm = \theta\,*\,16.3\,cm\\\frac{81.5}{16.3} = \theta\\\theta=5\,rad[/tex]
