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 in to 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 constructted 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 F and F~ 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.