Understanding Circle Circumference and Radius

Understanding Circle Circumference and Radius

Assessment

Interactive Video

Mathematics

5th - 8th Grade

Hard

Created by

Jackson Turner

FREE Resource

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.

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9 questions

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1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

128 pi feet

32 pi feet

64 pi feet

16 pi feet

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

32 feet

16 feet

64 feet

128 feet

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

64 feet

48 feet

32 feet

16 feet

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

8.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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

9.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

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