Law of the addition of vectors
(1) Parallelogram law of addition of vectors: It states that if two vectors are represented in direction and magnitude by two sides of a parallelogram, then their resultant is given by the diagonal passing through their common point.
(2) Triangle law of addition of vectors
If two vectors are represented in direction and magnitude by two adjacent sides of a triangle taken in the same order, then their resultant is given by the third side taken in opposite order.
(3) Polygon law of addition of vectors
If any number of vectors are represented in magnitude and direction by sides of a polygon taken in the same order, then their resultant is given by the closing side taken in opposite order.