area of a parallelogram is base x height 
base is 6+5=11 
height = 12 
11*12 = 132cm square 
or 
there are 2 triangles and 1 rectangle 
the triangles measure the same thing 
the formula for the area of a triangle is 1/2bh 
1/2*6*12  = 36 
area of rectangle 
is length x breadth 
5*12 = 60 
area of whole parallelogram = 60+36+36= 132cm square 
either ways you get the same answer