Sometimes it is necessary to resolve a force into two components in order to study its pulling or pushing effect in two specific directions. For example. in Fig. 2-8a. F is to be resolved into two components along the two members. defined by the u and v axes. In order to determine the magnitude of each component. a parallelogram is constructed first. by drawing lines starting from the tip of F, one line parallel to u,and the other line parallel to v . These lines then intersect with the v and u axes. forming a parallelogram. The force components Fu and Fv are then established by simply joining the tail of F to the intersection points on the u and v axes. Fig. 2-8b. This parallelogram can then be reduced to a triangle. which represents the triangle rule. Fig. 2-8c From this, the law of sines can then be applied to determine the unknown magnitudes of the components