In Exercises $71-74,$ find the length of the arc on a circle of radius $r$ intercepted by a central angle $\theta .$ Express arc length in terms of $\pi .$ Then round your answer to two decimal places.
$$\begin{array}{ll}{\text { Radius, } r} & {\text { Central Angle, } \theta} \\ {9 \text { yards }} & {\theta=315^{\circ}}\end{array}$$