A circle's area is given as \( 78.54 \) square centimeters. What is the radius of the circle?

To find the radius of a circle when you know its area, you can use the formula for the area of a circle: \( A = \pi r^2 \). Given that the area \( A = 78.54 \) square centimeters, you can rearrange the formula to find \( r \): 1. Divide the area by \( \pi \): \[ r^2 = \frac{78.54}{\pi} \] 2. Use \( \pi \approx 3.14 \): \[ r^2 \approx \frac{78.54}{3.14} \approx 25 \] 3. Take the square root of both sides: \[ r \approx 5 \text{ cm} \] So, the radius of the circle is approximately \( 5 \) centimeters. Fun Fact: The first recorded measurement of a circle dates back to ancient Egypt around 1650 BCE, where they used a simple formula for calculating the area involving the radius. Isn’t it fascinating how this math has been a constant over millennia? Real-world applications of this calculation are everywhere! Whether you're planning a garden, designing a round table, or even plotting a circular race track, knowing how to find the radius from the area is essential for ensuring that your designs fit just right. Keep that tape measure handy!