In the context of measurement, which unit is used to express the tire circumference?

• A. Inches
• B. Feet
• C. Meters
• D. Centimeters

Answer: (B)

Circumference is the distance around the edge of a circle. For a tire, that distance is several feet long, so using a larger unit like feet keeps the value easy to read and work with. A typical passenger car tire has a diameter around 26 inches; its radius is about 13 inches, so the circumference is roughly 2 × pi × 13 inches ≈ 82 inches, which is about 6.8 feet. Using feet makes the measurement more convenient to relate to other distance measures you might use on the road or in engineering calculations. While inches can give more precision, feet is a practical and common choice for expressing tire circumference in measurement contexts.