
If a sign is at equilibrium, then the individual forces acting upon the sign are balanced. Thus, there is no unbalanced force  the net force is 0 Newtons. In order for the net force to be 0 N, there must be a balance of both horizontal and vertical forces. If the sign is supported by two cables, each cable must pull with sufficient enough upward force to balance the weight of the sign (the downward force of gravity). Thus, if the sign weighs 100 N, the upward components of tension in each cable must together provide 100 N of upward force.
