Demo of Rectangle
height: 2, width: 2
Resetting height => 4, width => 3
height: 4, width: 3
area: 12
height: 4, width: 3

Demo of Square
height: undef, width: 2
Resetting height => 4, width => 3
height: 4, width: 3
area: 9
height: 3, width: 3