What is The diameter of a circle is 2 kilometers. What is the circle's area?

To find the area of a circle, you can use the formula ( A = \pi r^2 ), where ( r ) is the radius. The radius is half of the diameter, so with a diameter of 2 kilometers, the radius is 1 kilometer. Thus, the area is ( A = \pi (1^2) = \pi ) square kilometers, which is approximately 3.14 square kilometers.