Maxwell-Betti law of real work is a basic theorem in the structural analysis. Using this theorem, it can be established that the flexibility coefficients in compatibility equations, formulated to solve indeterminate structures by the flexibility method, form a symmetric matrix and this will reduce the number of deflection computations. The Maxwell-Betti law also has applications in the construction of influence lines diagrams for statically indeterminate structures. The Maxwell-Betti law, applies to any stable elastic structure (For example: a beam, truss, or frame etc.) on unyielding supports and at constant temperature, states.