Question

Working of sling based on parallelogram law of vector addition

Answer 1

Since there is no indicstion of which parallelogram it is being referred to here therefore here is an intuitive answer for you.

Let us assume that each vector has a path.

A person takes up path A and then ends up taking path B.

If we get the formula to be R=A+B then we get that the straight line W is the shortest path of them all.