Circumference and Perimeter of Circles

The video tutorial covers the concept of circumference and how to calculate it for circles and semicircles. It begins with an introduction to circumference, followed by a detailed example using a plate to demonstrate the calculation. The tutorial then explains semicircles, highlighting the importance of including the diameter in perimeter calculations. Several example problems are solved, and viewers are encouraged to practice with additional problems. The video concludes with a recap of key points.

What is the circumference of a circle?

• The area of the circle

• The distance around the circle

• The radius of the circle

• The distance across the circle

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

• 2πr

• πd

• πr²

• d/2

If a plate has a diameter of 9 inches, what is its circumference using π ≈ 3.14?

• 28.26 inches

• 27.12 inches

• 18.84 inches

• 31.42 inches

What is a semicircle?

• A quarter of a circle

• A full circle

• A circle with a hole

• Half of a circle

How do you calculate the perimeter of a semicircle?

• πd

• πd/2 + d

• πr²

• 2πr

For a semicircle with a diameter of 6 meters, what is the perimeter?

• 9.42 meters

• 15.42 meters

• 12.56 meters

• 18.84 meters

In the example with a 4-foot diameter semicircle, what is the calculated perimeter?

• 10.28 feet

• 9.42 feet

• 8.56 feet

• 12.56 feet

What is the perimeter of a semicircle with a 7 cm diameter?

• 10.99 cm

• 12.99 cm

• 17.99 cm

• 14.99 cm

If a semicircle has a radius of 15 inches, what is its perimeter?

• 77.1 inches

• 47.1 inches

• 30 inches

• 60 inches