Understanding Circle Circumference and Radius

The video tutorial explains how to solve a problem involving the circumference of a circle. It uses a spinning lawn sprinkler as an example, where the circumference is given as sixty-four pi feet. The tutorial demonstrates how to calculate the radius using the formula C = 2πr and applies this to determine if a person standing thirty feet from the sprinkler will get wet. The radius is found to be thirty-two feet, indicating that a person standing within this distance will be inside the circle and thus get wet.

What is the circumference of the circle covered by the lawn sprinkler?

• 128 pi feet

• 32 pi feet

• 64 pi feet

• 16 pi feet

Tags

CCSS.7.G.B.4

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

• C = pi r^2

• C = r/2

• C = 2 pi r

• C = pi d

Tags

CCSS.7.G.B.4

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

• The radius is twice the circumference

• The radius is half the circumference

• The circumference is the square of the radius

• The circumference is twice the radius times pi

Tags

CCSS.7.G.B.4

If the circumference of a circle is 64 pi feet, what is the radius?

• 32 feet

• 16 feet

• 64 feet

• 128 feet

Tags

CCSS.HSA.REI.A.1

What operation is performed to isolate the radius in the equation 64 pi = 2 pi r?

• Divide both sides by 2 pi

• Multiply both sides by pi

• Subtract pi from both sides

• Add 2 pi to both sides

Tags

CCSS.7.G.B.4

What is the radius of the circle if the circumference is given as 64 pi feet?

• 64 feet

• 48 feet

• 32 feet

• 16 feet

Tags

CCSS.7.G.B.4

If you are standing 30 feet away from the center of the circle, will you get wet?

• No, because 30 feet is exactly half the radius

• Yes, because 30 feet is the same as the radius

• No, because 30 feet is outside the radius of 32 feet

• Yes, because 30 feet is within the radius of 32 feet

Why would you get wet if you are standing 30 feet from the center of the circle?

• Because 30 feet is equal to the diameter

• Because 30 feet is outside the circle

• Because 30 feet is inside the circle

• Because 30 feet is the same as the circumference

What is the final conclusion about standing 30 feet away from the sprinkler?

• You will not get wet because you are at the center

• You will get wet because you are on the circumference

• You will get wet because you are inside the circle

• You will not get wet because you are outside the circle