Write ` vec P Q+ vec R P+ vec Q R` in the simplified form.

Explanation

Any vector `rightarrow{P Q}`, if the position vectors of point `{P}(vec{p})` and `{Q}(vec{q})` are know, can be written as `vec{q}-vec{p}`.

Let the position vectors of points `{P}, {Q}, {R} ` be `vec{p}, vec{q}, vec{r}`.

Then `vec{P Q}+vec{Q R}+vec{R P}`


`=(vec{q}-vec{p})+(vec{r}-vec{p})+(vec{q}-vec{r})=vec{0}`