Can someone provide me some input on the question below. Please respond.

A string trimmer is a tool for cutting grass and weeds; it utilizes a length of nylon "string" that rotates about an axis perpendicular to one end of the string. The string rotates at an angular speed of 39 rev/s, and its tip has a tangential speed of 64 m/s. What is the length of the rotating string?

tangential speed= anglarspeed*radius

solve for radius.