An auto race is held on a circular track. A car completes one lap in a time of 19.8 s, with an average tangential speed of 43.4 m/s. Find the following.

(a) the average angular speed
in rad/s

(b) the radius of the track
in meters

i know that tangential speed is T = r * theta

where r is the radius and theta is the distance.

however, i don't have r?

how do i solve for this.

also must i convert this 43.4 m/s into revolutions and then radians?

thanks alot.