Question

state and prove parallelogram law of
vector addition​

Answer 1

Explanation:

Parallelogram law of vector addition states that

if two vectors are considered to be the adjacent sides of a parallelogram, then the resultant of the two vectors is given by the vector that is diagonal passing through the point of contact of two vectors.

Answer 2

balance of that pic

R^2=p^2+Q^2+2×P×Q×COS theta

R=✓p^2+q^2+2pq cos theta..

i think you got it....✌️