Prob 1.1.10: Non-concurrent forces

Recall basic principles: transmissibility and parallelogram rule.

A reasonable solution.

An error:

In the last step the forces were combined using tip-to-tail, rather than the parallelogram rule.

The tip-to-tail method works only for concurrent forces. For non-concurrent forces, you need to use transmissibility, the paralleogram rule, and equivalent couples.