Understanding Circle Properties

The video tutorial explains how to determine the radius and diameter of a circle when given the circumference. It begins by discussing the relationship between circumference, radius, and diameter, emphasizing the role of pi as the ratio between circumference and diameter. The tutorial then demonstrates how to calculate the radius when the circumference is 49 pi and the diameter when the circumference is 1600 pi, using algebraic manipulation to solve for the unknowns.

What is the circumference of a circle if its radius is known to be r?

• 2 pi times r

• pi times r

• r squared

• pi divided by r

What is the standard definition of pi?

• The ratio of the radius to the diameter

• The ratio of the circumference to the diameter

• The ratio of the diameter to the circumference

• The ratio of the circumference to the radius

If the circumference of a circle is 49 pi, what is the radius?

• 12.25

• 98

• 49

• 24.5

What is the relationship between the diameter and the radius of a circle?

• Diameter is half the radius

• Diameter is twice the radius

• Diameter is equal to the radius

• Diameter is the square of the radius

If the circumference of a circle is 1600 pi, what is the diameter?

• 800

• 1600

• 3200

• 400

How can the circumference of a circle be expressed in terms of its diameter?

• Diameter squared

• Diameter divided by pi

• 2 pi times the diameter

• pi times the diameter

What happens to the value of pi when the circumference is divided by the diameter?

• It remains pi

• It doubles

• It becomes zero

• It becomes one

What is the formula for the circumference of a circle in terms of its radius?

• Radius divided by pi

• Radius squared

• 2 pi times the radius

• pi times the radius

If a circle's diameter is 1600 units, what is its circumference?

• 800 pi

• 400 pi

• 3200 pi

• 1600 pi

What is the diameter of a circle if its radius is 24.5 units?

• 49 units

• 24.5 units

• 12.25 units

• 98 units