i need help on this quick!!! cant figure out the measure of this circle

Answer:
Step-by-step explanation:
Angle SQO is an angle inscribed in a semicircle, so it's measure is 90 degrees. If angle SQO is congruent to angle MTN, then angle MTN is also 90 degrees. Angle MTN is a central angle. When a central angle intercepts an arc then the angle and the arc have congruent measures, so arc MN is 90 degrees.