Finding a Resultant Force. The Iwo component forces F1, and F2
acting on the pin in Fig.2-7a can be added together to form the resultant
force Fr= F1 + F2. as shown in Fig. 2-7b. From this construction. or using
the triangle rule. Fig. 2-7c. we can apply the law of cosines or the law of
sines to the triangle in order to obtain the magnitude of the resultant
force and its direction.