1. **State the problem:** We need to find the measure of arc $MO$ from the given picture. 2. **Identify the relevant information:** Since the picture is not provided here, typically, the measure of an arc in a circle is related to the central angle that intercepts the arc or can be found using properties of the circle such as inscribed angles, semicircles, or other given arcs. 3. **Formula and rules:** The measure of an arc is equal to the measure of its central angle. 4. **Intermediate work:** Without the picture or additional data, we cannot calculate the exact measure of arc $MO$. Please provide the central angle measure or other related arc measures. 5. **Conclusion:** To find the measure of arc $MO$, we need the central angle $\angle M O$ or other related information from the picture.