Consider a symmetrical roof truss structure comprising the vertical, diagonal and horizontal members. A free-body diagram is drawn to analyze the forces on DC and HC members using the method of section. Here, the loads and the lengths of the horizontal and vertical members are the known parameters. First, summing the moments about point A, the reaction force at E is calculated. Further, using the force equilibrium condition for the truss, the reaction force at A is determined. The symmetry of the truss ensures that both the reaction forces are equal. Now, a cut is made along a plane intersecting DC, HC and HG members, and a free-body diagram of the smaller section is drawn. Taking the summation of the moments about H gives the force along DC. The positive sign indicates the tensile force. The force along HC is resolved into its sine and cosine components, and trigonometry is used to estimate the angle theta. The moment equilibrium condition at E yields the force on HC, with the negative sign indicating the compressive force.