Circumference and Pi Calculations

The video tutorial explains how to determine the circumference of a circle, equating it to the perimeter. It introduces two formulas: one using the diameter and the other using the radius. The tutorial provides examples for both scenarios, demonstrating calculations and rounding techniques. It emphasizes the importance of using the correct value for pi, whether the exact value or an approximation, to ensure accurate results.

What is the circumference of a circle equivalent to?

• The area of the circle

• The radius of the circle

• The diameter of the circle

• The perimeter of the circle

Which formula can be used to calculate the circumference of a circle if the diameter is known?

• C = 2 x PI x R

• C = PI x D

• C = 2 x PI x D

• C = PI x R^2

If the diameter of a circle is 9 feet, what is the circumference in terms of Pi?

• 9 feet

• 18 feet

• 18PI feet

• 9PI feet

What is the decimal approximation of 9PI feet rounded to the nearest 100th?

• 28.27 feet

• 28.26 feet

• 28.28 feet

• 28.29 feet

Which formula is used to calculate the circumference of a circle if the radius is known?

• C = 2 x PI x D

• C = 2 x PI x R

• C = PI x R^2

• C = PI x D

If the radius of a circle is 3 inches, what is the circumference in terms of Pi?

• 6PI inches

• 3PI inches

• 9PI inches

• 12PI inches

What is the decimal approximation of 6PI inches rounded to the nearest 100th?

• 18.84 inches

• 18.85 inches

• 18.86 inches

• 18.87 inches

What value is often used to approximate Pi in calculations?

• 3.15

• 3.16

• 3.13

• 3.14

Why is it important to read the directions when using Pi in calculations?

• To prevent rounding errors

• To avoid using the wrong units

• To know whether to use the Pi key or 3.14

• To ensure the correct formula is used

What is the more accurate value of the circumference of a circle with a radius of 3 inches?

• 18.87 inches

• 18.86 inches

• 18.84 inches

• 18.85 inches