For these problems you can use the rotational versions of all your linear equations you've been using
So instead of d, you have theta, instead of v, angular velocity, and so on.
So the equation d=1/2at^2-Vi*t can be used but with the angle traveled in radians for d, angular acceleration for a, and initial angular velocity for Vi. That's not the particular equation you should use here though. This is similar to a problem where you know initial velocity and time, and want to find a. Then you can find d(which in this case is the total angle traveled in radians, so for example if it were like 6pi, the answer would be 3 revolutions)