<MBK- ?

The angle subtended by an arc at the center is double the angle subtended by it at any point on the remaining part of the circle. The arc AC subtends an angle of 38° at point B and 42° at point M. This implies that the arc AC corresponds to a central angle of 2 * 38° = 76° or 2 * 42° = 84°, which is a contradiction. Assuming the diagram is correct and the angles are as labeled, we can proceed. The angle