ACT SAT Prep Learn how to determine the circumference of a circle

The video tutorial explains how to calculate the circumference of a circle. It begins by defining key terms such as radius and diameter. The radius is the distance from the center to any point on the circle, while the diameter is the distance across the circle through the center. The tutorial then introduces the formulas for calculating the area and circumference of a circle. The area is given by πR², and the circumference is calculated using 2πR or π times the diameter. An example is provided where the radius is 4 inches, leading to a circumference of 8π.

What is the distance from the center of a circle to its edge called?

• Diameter

• Circumference

• Area

• Radius

Which of the following is the formula for the area of a circle?

• 2πR

• πR²

• πD

• R²

What does the circumference of a circle represent?

• The distance across the circle

• The distance from the center to the edge

• The space inside the circle

• The distance around the circle

If the radius of a circle is 4 inches, what is the circumference?

• 4π

• 8π

• 2π

• 16π

Which formula can be used to calculate the circumference of a circle?

• πD

• R²

• 2πR

• πR²