The area of the solid shape can be obtained by dividing the surfaces into different parts and finding each area and summing all the areas together.
Surface 1----> rectangle with dimensions 4km by 2km
[tex]\begin{gathered} A_1=l\times b \\ A_{1}=4\times2=8km^{2} \end{gathered}[/tex]
Surface 2 ---> rectangle with dimensions 8km by 2km
[tex]A_2=8\times2=16km^2[/tex]
Surface 3 ----> rectangle with dimensions 8km by 2km
[tex]A_3=8\times2=16km^2[/tex]
Surface 4 ----> triangle with a base 8km and a height of 3.9km
[tex]A_4=\frac{1}{2}\times b\times h=\frac{1}{2}\times8\times3.9=15.6km^2[/tex]
Surface 5 ----> triangle with base 8km and height 3.9km
[tex]A_5=\frac{1}{2}\times8\times3.9=15.6km^2[/tex]
The total surface area of the solid shape is
[tex]A_T=8+16+16+15.6+15.6=71.2km^2[/tex]
Option B is the answer.
