Triangleof Forces

Triangle of Forces is a deduction from the parallelogram of forces. [PARALLELOGRAM OF FORCES] There it was shown that if two forces acting on a point be represented in magnitude and direction by the lines B A, B D, their resultant is represented by B C, the diagonal of the parallelogram of which B A and B D are the sides. Now the force B C will be exactly balanced by the equal and opposite force, C B; hence C B will just neutralise the two forces B A and B D; but B D is equal to A C; hence C B will just neutralise B A and A C, or the three forces B A, A C, and C B are in equilibrium. These three forces are completely represented by the three sides of the triangle B A C, and, as the arrowheads show, they are taken in order. Hence it follows that if three forces acting at a point can be represented in magnitude and direction by the sides of a triangle taken in order they will be in equilibrium.