Answer:
Rectangle
Explanation:
The given quadrilateral has coordinates at: P (3,7), Q (-1,7), R (3, -1) and S (-1, -1).
The length of PQ is given by:

The length of QS is

The length of RS is

The length of PR is

The slope of PQ is

The slope of QS is

The slope of RS

The slope of PR is

The quadrilateral has pair of parallel sides equal and adjacent sides perpendicular.
This is a rectangle