Parallelogram Law of Forces
When two forces act at a particular point on the plane that shows two adjacent sides of parallelogram and have magnitude and direction, the resultant will represent the diagonal of the parallelogram passing though the same point having its magnitude and direction. This is parallelogram law of forces.
Triangular Law of Forces
If two forces act at a point on the plane having magnitude and direction, then the closing side of the triangle gives the resultant with its magnitude and direction (taken in the same order). This is called triangular law of forces.