Answer:
The area of the following figure is 400
.
Explanation:
On the left side of the figure, you'll see that there is a half-circle with a diameter of 20 meters. On the right side of the figure, there is a gap for a half-circle with a diameter of 20 meters. To make the calculation process easier, you can imagine that you take the half-circle from the left side and fit it onto the gap on the right in order to form a 20 meters by 20 meters square. Now you can just multiply the side lengths together to find the area, which will be 20 * 20 = 400
.