The measure of an arc, commonly referred to as its arc measure, is equal to the measure of its corresponding central angle. In the diagram, the measure of $\overgroup{AB}$ is equal to the measure of $\angle ACB.$

Suppose the measure of $\overgroup{AB}$ is given as $\theta .$ The measure of the corresponding major arc $\overgroup{ADB}$ can be found by subtracting $\theta$ from $360^{\circ },$ the measure of the entire circle.