Question: Calculate the area of the circle below.
Give your answer in terms of $\pi$.
Circle diagram: a circle is centered near the lower middle of the page with a radius labeled $5$ km, shown as a vertical line from the center to the bottom edge of the circle.
1. **State the problem:** We need to find the area of a circle with radius $5$ km.
2. **Formula for the area of a circle:** The area $A$ of a circle is given by the formula:
$$A = \pi r^2$$
where $r$ is the radius of the circle.
3. **Substitute the radius:** Here, $r = 5$ km, so:
$$A = \pi \times 5^2$$
4. **Calculate the square:**
$$5^2 = 25$$
So,
$$A = \pi \times 25$$
5. **Final answer:**
$$A = 25\pi$$ km$^2$
This is the area of the circle in terms of $\pi$.