Exploring the Circumference of Circles

The video tutorial covers the concept of circumference, explaining how to calculate it using the formula C = πd. It provides examples of finding circumference in terms of pi and rounding to the nearest tenth. The tutorial emphasizes the importance of understanding each step for homework, tests, and quizzes. It also highlights the need to distinguish between radius and diameter when using the formula.

What is the formula for the circumference of a circle?

• C = pi * diameter

• C = 2 * pi * radius

• C = diameter / pi

• C = radius / 2 * pi

Why is it important to write down all steps when calculating circumference?

• To make it easier to remember the formula

• To ensure accuracy in calculations

• To earn full points on homework and tests

• All of the above

If the diameter of a circle is 15 cm, what is the circumference in terms of pi?

• 7.5 pi cm

• 30 pi cm

• 45 pi cm

• 15 pi cm

How do you calculate the diameter if only the radius is given?

• Multiply the radius by pi

• Subtract pi from the radius

• Multiply the radius by 2

• Divide the radius by 2

What is the circumference of a circle with a radius of 10.5 meters?

• 20.5 pi meters

• 10.5 pi meters

• 21 pi meters

• 42 pi meters

When rounding to the nearest tenth, what placeholder is used after rounding up?

• 0.1

• 0.0

• 1.0

• 0.5

What is the correct way to round 109.9557429 to the nearest tenth?

• 110.0

• 110.1

• 109.9

• 109.95

If the diameter of a circle is 35 inches, what is the circumference rounded to the nearest tenth?

• 110.0 inches

• 109.9 inches

• 120.0 inches

• 100.0 inches

What is the diameter if the radius is 3.25 meters?

• 3.25 meters

• 1.625 meters

• 6.5 meters

• 9.75 meters

What is the circumference of a circle with a diameter of 6.5 meters, rounded to the nearest tenth?

• 20.4 meters

• 13.0 meters

• 6.5 meters

• 32.5 meters