THE POLYGON LAW-if (n-1) similar vectors acting at a point in a plane can be represented both in magnitude and direction by the (n-1) consecutive sides of a n-sided polygon then the n-th side will represent the resultant vector in the reverse order.

 polygon law- if a number of vectors are represented in magnitude and direction by sides of an incomplete polygon taken in order then the resultant is represented in magnitude and direction by the remaining side taken in opposite order.