25. OM = x. Find x.

1. OB is the radius and BM is a tangent. Therefore, angle OBM = 90 degrees.
2. In right-angled triangle OBM, angle BOM = 180 - 90 - 60 = 30 degrees.
3. OM is the hypotenuse. OB is opposite to angle OMB. OB = OM * sin(60) = x * sqrt(3)/2. This is not possible as OM is the hypotenuse and must be greater than OB. There is not enough information to solve.