Praxis Core Academic Skills for Educators: Mathematics (5733)GeometryEasy
A gardener is planning to install a circular flower bed with a diameter of 10 feet. What is the approximate circumference of the flower bed?
- A31.4 feet
- B15.7 feet
- C78.5 feet
- D62.8 feet
Show answer & explanationAnswer & explanation
Correct answer: A. 31.4 feet
The circumference of a circle is calculated using the formula C = πd, where d is the diameter. Given a diameter of 10 feet, the circumference is approximately 3.14 * 10 = 31.4 feet.
Why the other options are wrong
- B. This would be the circumference if the radius was 5 feet and the formula used was C = πr, which is incorrect.
- C. This is approximately the area of the circle, not the circumference.
- D. This is double the correct circumference, possibly from using C = 2πd.
Circumference of a Circle
The distance around the edge of a circle.
- Calculated using C = πd or C = 2πr.
- π (pi) is approximately 3.14159.
- Units are linear (e.g., feet, meters).
Memory trick: Circumference is the 'circle' around, Area is the 'apple' inside.