Explain why it is not necessary to use the principle of moments to find the resultant of a concurrent force system. If the first and last lines of a funicular polygon are parallel, but not collinear,...

Explain why it is not necessary to use the principle of moments to find the resultant of a concurrent force system.

If the first and last lines of a funicular polygon are parallel, but not collinear, explain how you would calculate the resultant, with a diagram.