A circle has a circumference of 153.86 units. What is the radius of the circle? Use 3.14 for \( \pi \) and enter your answer as a decimal.

To find the radius of a circle given the circumference, we can use the formula \( C = 2\pi r \). Rearranging this formula to solve for the radius \( r \), we get: \[ r = \frac{C}{2\pi} \] Substituting the given circumference \( C = 153.86 \) and \( \pi \approx 3.14 \): \[ r = \frac{153.86}{2 \times 3.14} \] Calculating that: \[ r = \frac{153.86}{6.28} \approx 24.5 \text{ units} \] So, the radius of the circle is approximately 24.5 units. To visualize circles throughout history, think about ancient civilizations like the Greeks and Egyptians, who were among the first to study and apply geometric principles involving circles. The circle's perfect symmetry made it a symbol of eternity and unity in their cultures. Archimedes even developed formulas that are foundational to our understanding of circles today! In real-world applications, knowing the radius is super handy! For instance, if you're planning to build a circular garden or a playground, understanding the radius helps you determine how much space you need. You can also calculate areas and other important measurements, making it a vital skill for anyone involved in design or architecture.