.
state triangle and parallelogram law of vector addition
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The triangle rule of adding vectors:
If the vectors AB and BC are two sides of the triangle ABC, then the sum
of the vectors AB and BC (in this order and orientation) is the third side AC of the triangle.
The parallelogram rule of adding vectors.
If two vectors AB and AD have the common initial point A, then the sum
of the vectors AB and AD is the vector AC which is the diagonal of the parallelogram ADCB
built on the sides AB and AD.
See the lesson Vectors in a plane in this site.
