If the rim of the wheel and its hub maintain contact with the three stationary tracks as the wheel rolls, it is neccessary that slipping occurs at the hub A if no slipping occurs at B. Under these conditions, what i

If the rim of the wheel and its hub maintain contact with the three stationary tracks as the wheel rolls, it is neccessary that slipping occurs at the hub A if no slipping occurs at B. Under these conditions, what is the speed at A if the wheel has an angular velocity ?