Check whether we have two equal sides for each rectangle and that area of each rectangle formed is the same
for ( let i = 0 ; i < 2 * n ; i = i + 2 ) { if ( arr [ i ] != arr [ i + 1 ] arr [ 4 * n - i - 1 ] != arr [ 4 * n - i - 2 ] arr [ i ] * arr [ 4 * n - i - 1 ] != area ) {