11. Find the side and diagonals of the square

The points \(A(9, 3)\), \(B(18, 3)\), \(C(18,12)\) and \(D(9,12)\) in order are the vertices of a square. Find the value of distance and diagonals of the square.

 

The distance between the points is  and the diagonal is √160√165√161√162 this is equal to all the points which make the square shape.