Answer:The fourth vertex of the square is (3,1) .
Explanation:
First,you need to plot the points in coordinate plane. After, plotting the points you will get a incomplete square. By, imagining the point (3,1) is the fourth vertex of square count the boxes on the square and it proves the relation of perimeter and area of square. So,the answer is (3,1) .
Note: No, coordinate plane is here so I have explained without coordinate