let us draw a line as shown in picture.
Now the area of large rectangle is
(A1) =1.3×1.8=2.34 sq. Km
and the area of small rectangle is
(A2)=1×0.65=0.65 sq. Km
therefore, the area of given figure is
A=A1-A2
=2.34-0.65
=1.69 sq. Km
