Since points A, E, and B are collinear, the Segment Addition Postulate states that the length of AE plus the length of EB equals the length of AB. Therefore, 6 + 4 = 10, so AB = 10. This is justified by the Segment Addition Postulate, which states that if three points are collinear, then the distance between the first point and the second point added to the distance between the second point and the third point is equal to the distance between the first point and the third point.
