Answer: 464 km²
Explanation:
We will break this shape up into two parts. You can do this in two different ways, see attached for how I did it.
Area of a rectangle is A = L * W;
40 km * 9 km = 360 km²
13km * 8 km = 104 km²
Now we will add them together for total area:
360 km² + 104 km² = 464 km²