To calculate the area of a circle, we use the formula:

$A = \pi r^2$

Where:

• $A$ is the area,
• $\pi$ is approximately 3.14159,
• $r$ is the radius.

Given that the radius $r = 5$, we can substitute this value into the formula:

$A = \pi \times (5)^2 = \pi \times 25 \approx 3.14159 \times 25 \approx 78.54$

Thus, the area of the circle is approximately 78.54 square units.

Would you like further details on this? Let me know if you have any questions!

Here are some related questions:

1. How does changing the radius affect the area of a circle?
2. What would the area be if the radius were doubled?
3. How is the circumference of a circle related to the radius?
4. What is the area of a circle with a radius of 10?
5. How can the area formula for a circle be derived from geometry?

Tip: Remember that the area grows quadratically with the radius. Doubling the radius will quadruple the area!