Explanation:
Make the points diagonal corners of the square...the distance,d between = 12 units .... then the side length using Pyhtagorean theorem is found via :
d^2 = s^2 *+ s^2
12^2 = 2s^2
144 = 2 s^2
s^2 = 72
s = sqrt (72)
and then, the area = s x s = 72 units^2