Method of Joints:

At each joint the forces in the members meeting at the joint and the loads at the joint, if any, constitute a system of concurrent forces. Hence, two independent equations of equilibrium can be formed about each joint. For starting analysis, a joint is selected where there are only two unknown forces. Many a time such a joint can be identified only after finding the reaction at the support by considering the entire frame. Then making use of the two equations of equilibrium for the system of forces acting at the joint those two unknown forces are found. Then the next joint is selected for analysis where there are now only two unknown forces. Thus, the analysis proceeds from joint to joint to find the forces in all the members.