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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.
 
Answer variants:
81
79
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83
The distance between the points is 
and the diagonal is  this is equal to all the points which make the square shape.