Exploring Circles and Their Circumference

This video tutorial covers the concepts of circles, radius, diameter, and circumference. It explains how to calculate the radius and diameter of a circle, and how to find the circumference using pi. The tutorial includes practical examples and real-life applications, such as finding the circumference of a pizza or a pond. It also discusses the perimeter of semicircles, providing step-by-step calculations and emphasizing the importance of understanding these geometric concepts.

What is the radius of a circle if its diameter is 30 inches?

• 7.5 inches

• 15 inches

• 30 inches

• 60 inches

If the radius of a circle is 8.2 cm, what is the diameter?

• 16.4 cm

• 4.1 cm

• 8.2 cm

• 12.3 cm

What is the value of pi as used in school calculations?

• 3.142

• 3.14

• 22/7

• 3.14159

How do you calculate the circumference of a circle using its radius?

• C = 2πr

• C = πd

• C = πr^2

• C = 2r

What is the circumference of a pizza with a radius of 8 inches?

• 16 inches

• 100.48 inches

• 25.12 inches

• 50.24 inches

Calculate the circumference of a cookie with a diameter of 15 cm.

• 15 cm

• 62.8 cm

• 30 cm

• 47.1 cm

What is the circumference of a plate with a radius of 6 inches?

• 18.84 inches

• 12 inches

• 24 inches

• 37.68 inches

How much rock material is needed to encircle a pond with a diameter of 6.3 feet?

• Approximately 20 feet

• Approximately 10 feet

• Approximately 30 feet

• Approximately 15 feet

What is the perimeter of a semicircle rug with a diameter of 3 feet?

• 9.42 feet

• 6 feet

• 7.71 feet

• 4.71 feet

Find the perimeter of a slice of watermelon with a radius of 12 cm.

• 75.36 cm

• 61.68 cm

• 24 cm

• 37.68 cm