Given:
Given that the diameter of the circle is 10 kilometers.
We need to determine the area of the circle.
Radius of the circle:
The radius of the circle can be determined using the formula,
[tex]r=\frac{d}{2}[/tex]
Substituting d = 10, we get;
[tex]r=\frac{10}{2}[/tex]
[tex]r=5[/tex]
Thus, the radius of the circle is 5 kilometers.
Area of the circle:
The area of the circle can be determined using the formula,
[tex]A=\pi r^2[/tex]
Substituting r = 5, we get;
[tex]A=(3.14)(5)^2[/tex]
[tex]A=(3.14)(25)[/tex]
[tex]A=78.5[/tex]
Thus, the area of the circle is 78.5 square kilometers.