Find the coordinates of the vertices of a rectangle placed in III quadrant, in the cartesian plane with length p units on x-axis and breadth q units on y-axis.

Since the rectangle is placed in 3rd quadrant one vertex is of form (-p ,-q)

Therefore other two vertices lie in the negative part of x-axis and y-axis

the other two vertices are (0,-q) and (-p,0)

and the fourth vertex is the origin

**
**