Question

Total surface area of the drawing

Answer 1

The pentagon's area is the sum of the 5 triangles that comprise it.  This is

$5( \frac{1}{2}bh) \times 2=5(9)(6.2)= 279$

where the factor of 2 accounts for the top and bottom.  The walls have an area of 5 rectangles

$5(bh)=5(9)(6)=270 \\ \\ 279+270=549km^2$