According to the moment-area theorem, the change in slope for a particular beam equals the end shear force of the beam when it is loaded with the diagram. Thus, for the beam under consideration, the rotations β A and β B, shown in Figure 11.2, are obtained as follows: Similarly, taking the moment about end A to determine β B suggests the ... The moment diagram is a visual representation of the area under the shear force diagram. That is, the moment is the integral of the shear force. If the shear force is constant over an interval, the moment equation will be in terms of x (linear).