10 Real-World Circumference Examples with Solved Solutions (Grade 7)

📚 Quick Study Guide

• 📏 Definition: Circumference is the distance around a circle.
• ➗ Diameter: The distance across a circle through the center.
• 🔴 Radius: The distance from the center of a circle to any point on its edge (half the diameter).
• 🧮 Formula 1 (using diameter): $C = \pi d$, where $C$ is the circumference, $\pi$ (pi) is approximately 3.14159, and $d$ is the diameter.
• 📐 Formula 2 (using radius): $C = 2\pi r$, where $C$ is the circumference, $\pi$ (pi) is approximately 3.14159, and $r$ is the radius.
• 💡 Key Tip: Remember to use the correct units (e.g., cm, m, inches) in your answer!

Practice Quiz

1. What is the circumference of a circular pizza with a diameter of 12 inches?
   1. 37.68 inches
   2. 18.84 inches
   3. 75.36 inches
   4. 6.28 inches
2. A bicycle wheel has a radius of 30 cm. How far does the bicycle travel in one revolution of the wheel?
   1. 94.2 cm
   2. 188.4 cm
   3. 47.1 cm
   4. 60 cm
3. A circular garden has a diameter of 8 meters. What is the length of fencing needed to enclose the garden?
   1. 50.24 meters
   2. 25.12 meters
   3. 12.56 meters
   4. 16 meters
4. A round table has a radius of 2.5 feet. What is the circumference of the table?
   1. 7.85 feet
   2. 15.7 feet
   3. 19.625 feet
   4. 31.4 feet
5. The circumference of a circular swimming pool is 50 meters. What is the diameter of the pool?
   1. 15.92 meters
   2. 7.96 meters
   3. 25 meters
   4. 314 meters
6. A circular clock has a radius of 10 cm. What is the distance around the edge of the clock?
   1. 62.8 cm
   2. 31.4 cm
   3. 20 cm
   4. 100 cm
7. A coin has a diameter of 2.5 cm. What is its circumference?
   1. 3.925 cm
   2. 7.85 cm
   3. 15.7 cm
   4. 1.25 cm