Question 1136754
show that all sides are equal
distance formula sqrt (difference in x s ^2+ difference in y s ^2)
AB has distance 5 units (sqrt 25)
BC and AD have distance 2 units
The quadrilateral is not a square.

One may also use slopes to see if two opposite lines have the same slope and are perpendicular to the two other opposite lines.

Sketch a graph and plot a couple of points.  It is obvious the figure is not a square.