Answer:
120 km squared.
Explanation:
The shape shown has 5 sides: three rectangles and 2 triangles.
If you examine each triangle closely, they are 3-4-5 triangles. The area of one triangle is 3 * 4 * 1/2 = 12 * 1/2 = 12 / 2 = 6. Since there are two triangles, the total area of the triangles is 6 * 2 = 12 km squared.
The three rectangles have the same length, but their widths differ. They all have a side length of 9 km, but the largest rectangle has a width of 5 km, the medium has a width of 4 km, and the smallest has a width of 3 km.
So, the rectangles' areas added up will be (9 * 5) + (9 * 4) + (9 * 3) = 45 + 36 + 27 = 108 km squared.
And so, the total surface area is 12 km squared + 108 km squared, or 120 km squared.
Hope this helps!