**ADDITION OF VECTORS USING POLYGON METHOD**** **

Let three coplanar vectors f_{1} F_{2}and F; act at O_{1}. (Ref Fig. 2.3(a))

We take a point 02 in the same plane and from 02 we draw the vectors F_{1} F_{2}and F_{3 }in any order to some scale. We close the polygon by dashed vector which represents the sum of the Vectors.

Fig. 2.3 (b) and 2.3(c) both give the same vector.

The polygon summation process can be used as a graphical process. We can also use trigonometry to find the final vector.

Suppose Coplanar vectors A, B, C and D are given. We have to form A+ B-C-D. Refer Fig. 2.4(a) and 2.4(b)