Make the tangent of circle (x - 6) ^ 2 + y ^ 2 = 4 through origin 0, then the tangent length is

Make the tangent of circle (x - 6) ^ 2 + y ^ 2 = 4 through origin 0, then the tangent length is

Let the center of the circle be a and the tangent point be B
OA=6,AB=r=2
∴OB=4√2