OK = 6, ZMON = ?, MK, NK = ?

In right triangle ONM, ON = OK = 6. Since OK is perpendicular to MK, ZOKM = 90 degrees. Since ON is perpendicular to NK, ZONK = 90 degrees. Triangle ONM is isosceles with ON = OM = 6. Triangle ONK is isosceles with ON = OK = 6. Since MK and NK are tangents from K to the circle, OM = ON = OK = 6. Triangle MON is isosceles with OM = ON. Triangle MOK is congruent to triangle NOK. ZMON = 2 * ZMOK. In triangle OMK, OM = 6. We need more information to solve for ZMON, MK, and NK.