Consider a truss structure with frictionless joints fixed to a wall and roller support on ground. If a force of 150 N is applied to joint A, then determine the forces in each member of the truss. The forces at each joint can be determined using the method of joints. Firstly, the angle between the members AC and AB can be determined as the tan inverse of the ratio of the length of BC and AB. Secondly, draw a free-body diagram of joint A and resolve the forces into their components. By applying the equations of equilibrium, the unknown forces can be determined. Next, by drawing the free-body diagrams of joints B and C, and using equilibrium equations, the unknown forces at joints B and C can be determined. Finally, draw a free-body diagram of joints D and E. For members CD and EF, resolve the forces into the horizontal and vertical components. The unknown forces at joints D and E can be determined using the equations of equilibrium.