Exploring the Circumference of a Circle

The video tutorial reviews the concept of circumference, covering key vocabulary such as radius, diameter, and circumference. It explains the relationship between radius and diameter, and how to calculate circumference using pi. The tutorial includes example problems to reinforce understanding.

What is the radius of a circle?

• Twice the distance across the circle

• The full distance across the circle

• Half the distance across the circle

• The distance around the circle

If the diameter of a circle is 20 cm, what is the radius?

• 5 cm

• 20 cm

• 10 cm

• 40 cm

What is the formula to find the diameter if the radius is known?

• Diameter = 2 * Radius

• Diameter = Radius + 2

• Diameter = Radius - 2

• Diameter = Radius / 2

What is the value of pi used in classroom calculations?

• 22/7

• 3.14

• 3.14159

• 3.142

How do you find the radius from the diameter?

• Multiply the diameter by 2

• Divide the diameter by 2

• Multiply the diameter by 0.5

• Subtract 2 from the diameter

How do you calculate the circumference if the diameter is given?

• Circumference = 2 * Pi * Diameter

• Circumference = Pi * Diameter

• Circumference = Pi * Radius

• Circumference = 2 * Pi * Radius

What is the circumference of a circle with a radius of 7 cm using Pi = 3.14?

• 14 cm

• 21.98 cm

• 43.96 cm

• 44 cm

What is the formula for circumference using the radius?

• Circumference = 2 * Pi * Radius

• Circumference = 2 * Pi * Diameter

• Circumference = Pi / Radius

• Circumference = Pi * Diameter

If the radius of a tire is 22 cm, what is the circumference?

• 138.16 cm

• 44 cm

• 88 cm

• 276.32 cm

What is the diameter of a circle if the radius is 4.5 mm?

• 2.25 mm

• 9 mm

• 4.5 mm

• 18 mm