A positive tau ((+, rest energy = 1777 MeV) is moving with 2200 MeV of kinetic energy

Question:

A positive tau ((+, rest energy = 1777 MeV) is moving with 2200 MeV of kinetic energy in a circular path perpendicular to a uniform 1.20 T magnetic field.
(a) Calculate the momentum of the tau in kilogram-meters per second. Relativistic effects must be considered.
(b) Find the radius of the circular path.