Answer:
219.25 km^2.
Explanation:
We can split this into 2 rectangles and 1 semicircle.
The area of the longer rectangle whose longest side is , at the bottom, 21 km and width 6 km = 21 * 6 = 126 km^2.
Area of the smaller rectangle = 6 * 9 = 54 km^2.
The diameter of the semicircle = 6 + 9 - 9 + 4 = 10 km so its radius is 5 km.
The area of the semicircle = 1/2 pi r^2
= 1/2 * 3.14 * 5^2
= 39.25 km^2.
So the area of the whole figure = 126 + 54 + 39.25
= 219.25 km^2.