10. Calculate the sides of the parallelogram

The points \(A(20, 9)\), \(B(-15, -3)\), \(C(-15,-18)\) and \(D(20,-6)\) in order are the vertices of a Parallelogram. In the parallelogram the opposite sides are equal. Calculate the side values of the parallelogram using distance formula.

 

\(AB =\) $\sqrt{i}$.