If the following vertices form a parallelogram, find the values of the unknown variables.
 
\(A = (\)10, \(r)\), \(B = (\)26, 20\()\), \(C = (\)86, 28\()\) and \(D = (s\), 28\()\).
 
Figure 13.png
 
\(r =\)
 
\(s =\)