Call Now to Set Up Tutoring:

(888) 888-0446

Pre-Algebra : Circumference of a Circle

Study concepts, example questions & explanations for Pre-Algebra

Create An Account

All Pre-Algebra Resources

11 Diagnostic Tests 177 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #1 : Circumference Of A Circle

Becky's house is surrounded by a circular lake that Becky runs around each day. If Becky wants to figure out the distance she runs around the lake, what formula should Becky use?

Possible Answers:

$C=\Pi r^{2}$

None of the other answers

$C=l\cdot w$

$C=2\Pi r$

$P=d\Pi$

Correct answer:

$C=2\Pi r$

Explanation:

Becky should use the circumfrence formula to find the distance she runs of a lake.

Correct Answer: $C=2\Pi r$

Report an Error

Example Question #2 : Circumference Of A Circle

What is the circumference of a circle with an area equal to $81\pi$ ?

Possible Answers:

$4.5\pi$

$9\pi$

$36\pi$

$18\pi$

Correct answer:

$18\pi$

Explanation:

Using the area, solve for the radius:

$A=r^2\pi$

$81\pi=r^2\pi$

Divide by $\pi$ :

81=r^2

Take the square root:

$\sqrt{81}=9=r$

Plug this radius into the formula for the circumference:

$C=2r\pi=2(9)\pi=18\pi$

Report an Error

Example Question #1 : Circumference Of A Circle

What is the circumference of a circle with a radius equal to ?

Possible Answers:

$49\pi$

$7\pi$

$14\pi$

$196\pi$

Correct answer:

$14\pi$

Explanation:

The circumference can be solved using the following equation:

$C=2r\pi=2(7)\pi=14\pi$

Report an Error

Example Question #2 : Circumference Of A Circle

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

Possible Answers:

$8\pi$

$16\pi$

$16\pi^{2}$

$28\pi$

Correct answer:

$16\pi$

Explanation:

The circumference can be solved using the following equation:

$C=2r\pi$

Where represents the radius. Therefore, when we substitute our radius in we get:

$=2(8)\pi =16\pi$

Report an Error

Example Question #1 : Know And Use The Formulas For The Area And Circumference Of A Circle: Ccss.Math.Content.7.G.B.4

The perimeter of a given rectangle is equal to the circumference of a given circle. The circle has radius inches; the width of the rectangle is $8 \pi$ inches. What is the length of the rectangle?

Possible Answers:

$14 \pi$ inches

$22 \pi$ inches

$(30 - 8 \pi )$ inches

$44 \pi$ inches

$7\pi$ inches

Correct answer:

$22 \pi$ inches

Explanation:

The circumference of a circle with radius inches is

$C = 2 \pi r = 2 \pi \cdot 30 = 60 \pi$ inches.

The perimeter of the rectangle is therefore $60 \pi$ inches. To find its length, substitute $W = 8\pi$ and $P = 60\pi$ into the equation and solve for :

2 L + 2W = P

$2 L + 2 \cdot 8 \pi = 60 \pi$

$2 L + 16 \pi = 60 \pi$

$2 L + 16 \pi - 16 \pi = 60 \pi - 16 \pi$

$2 L =44 \pi$

$2 L \div 2=44 \pi \div 2$

$L = 22\pi$ inches

Report an Error

Example Question #3 : Circumference Of A Circle

Determine the circumference of the circle if the radius is 20.

Possible Answers:

$20\pi$

$80\pi$

$400\pi$

$200\pi$

$40\pi$

Correct answer:

$40\pi$

Explanation:

Write the formula for circumference.

$C=2\pi r$

Substitute the radius and solve.

$C=2\pi(20) = 40\pi$

Report an Error

Example Question #4 : Circumference Of A Circle

Given the area of the circle is $9\pi$ , what is the circumference of the circle?

Possible Answers:

$6\pi$

$6\pi +6$

$3+3\pi$

Correct answer:

$6\pi$

Explanation:

Write the formula for the area of a circle.

$A=\pi r^2$

Substitute the area.

$9\pi=\pi r^2$

r^2=9

r=3

Write the circumference of the circle.

$C=2\pi r$

Substitute the radius.

$C=2\pi (3) = 6\pi$

Report an Error

Example Question #5 : Circumference Of A Circle

Find the circumference of a circle with an area of $\pi^2$ .

Possible Answers:

$\pi \sqrt{\pi}$

$3\pi$

$2\pi \sqrt{\pi}$

$2\pi ^3$

$3\pi^2$

Correct answer:

$2\pi \sqrt{\pi}$

Explanation:

Write the area formula in order to find the radius.

$A=\pi r^2$

Substitute the area.

$\pi ^2=\pi r^2$

$r^2=\pi$

$r=\sqrt{\pi}$

Write the circumference formula.

$C=2\pi r$

Substitute the radius.

$C=2\pi \sqrt{\pi}$

Report an Error

Example Question #6 : Circumference Of A Circle

Determine the circumference of the circle if the radius is $2\pi$ .

Possible Answers:

$4\pi$

$4\pi ^3$

$8\pi$

$4\pi ^2$

$2\pi ^2$

Correct answer:

$4\pi ^2$

Explanation:

Write the formula for the circumference of a circle.

$C=2\pi r$

Substitute the radius into the formula.

$C=2\pi (2\pi) = 4\pi ^2$

Report an Error

Example Question #7 : Circumference Of A Circle

Find the circumference of a circle with a radius of $\sqrt2$ .

Possible Answers:

$2\pi$

$\frac{\sqrt{2\pi}}{2}$

$\frac{\sqrt2}{2} \pi$

$4\pi$

$2\pi \sqrt{2}$

Correct answer:

$2\pi \sqrt{2}$

Explanation:

Write the formula to find the circumference of a circle.

$C=2\pi r$

Substitute the radius.

$C=2\pi \sqrt{2}$

Report an Error

View Pre-Algebra Tutors

Ajay
Certified Tutor

St. Francis University, Bachelor of Accountancy, Accounting.

View Pre-Algebra Tutors

Mark
Certified Tutor

Rochester Institute of Technology, Bachelor of Science, Game and Interactive Media Design. Rochester Institute of Technology,...

View Pre-Algebra Tutors

William
Certified Tutor

Don Bosco Salesian College, Bachelor of Science, Natural Sciences. Universidad Rafael Landívar, Bachelor in Arts, Business Ad...

All Pre-Algebra Resources

11 Diagnostic Tests 177 Practice Tests Question of the Day Flashcards Learn by Concept

Popular Subjects

Physics Tutors in Seattle, Physics Tutors in Houston, ACT Tutors in Atlanta, MCAT Tutors in Atlanta, SSAT Tutors in Dallas Fort Worth, ISEE Tutors in Denver, Biology Tutors in Phoenix, Calculus Tutors in San Diego, Statistics Tutors in Los Angeles, Statistics Tutors in Atlanta

Popular Courses & Classes

Spanish Courses & Classes in Chicago, ISEE Courses & Classes in Phoenix, ACT Courses & Classes in Miami, ISEE Courses & Classes in Denver, ISEE Courses & Classes in Houston, ISEE Courses & Classes in Dallas Fort Worth, ISEE Courses & Classes in New York City, GMAT Courses & Classes in Phoenix, ISEE Courses & Classes in Miami, GRE Courses & Classes in Miami

Popular Test Prep

GRE Test Prep in New York City, GRE Test Prep in Dallas Fort Worth, SSAT Test Prep in San Francisco-Bay Area, ISEE Test Prep in Washington DC, GMAT Test Prep in Seattle, LSAT Test Prep in Philadelphia, ISEE Test Prep in Phoenix, ISEE Test Prep in San Diego, GMAT Test Prep in Chicago, SAT Test Prep in Dallas Fort Worth

DMCA Complaint

If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing the information described below to the designated agent listed below. If Varsity Tutors takes action in response to an Infringement Notice, it will make a good faith attempt to contact the party that made such content available by means of the most recent email address, if any, provided by such party to Varsity Tutors.

Your Infringement Notice may be forwarded to the party that made the content available or to third parties such as ChillingEffects.org.

Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially misrepresent that a product or activity is infringing your copyrights. Thus, if you are not sure content located on or linked-to by the Website infringes your copyright, you should consider first contacting an attorney.

Please follow these steps to file a notice:

You must include the following:

A physical or electronic signature of the copyright owner or a person authorized to act on their behalf; An identification of the copyright claimed to have been infringed; A description of the nature and exact location of the content that you claim to infringe your copyright, in \ sufficient detail to permit Varsity Tutors to find and positively identify that content; for example we require a link to the specific question (not just the name of the question) that contains the content and a description of which specific portion of the question – an image, a link, the text, etc – your complaint refers to; Your name, address, telephone number and email address; and A statement by you: (a) that you believe in good faith that the use of the content that you claim to infringe your copyright is not authorized by law, or by the copyright owner or such owner’s agent; (b) that all of the information contained in your Infringement Notice is accurate, and (c) under penalty of perjury, that you are either the copyright owner or a person authorized to act on their behalf.

Send your complaint to our designated agent at:

Charles Cohn Varsity Tutors LLC
101 S. Hanley Rd, Suite 300
St. Louis, MO 63105

Or fill out the form below:

Do not fill in this field

Contact Information

* Full legal name

Company name

* Phone number

* Email address

Address

* Address1

Address2

* City

* State

* Zipcode

* Country

Complaint Details

* URL of copyrighted work (where your original material is located)

* Please describe the copyrighted work so that it may be easily identified

I am the owner, or an agent authorized to act on behalf of the owner of an exclusive right that is allegedly infringed.

I have a good faith belief that the use of the material in the manner complained of is not authorized by the copyright owner, its agent, or the law.

This notification is accurate.

I acknowledge that there may be adverse legal consequences for making false or bad faith allegations of copyright infringement by using this process.

* Signature (your digital signature is legally binding)

HIGH SCHOOL

GRADUATE SCHOOL

K-8

Search 50+ Tests

math tutoring

science tutoring

foreign languages

elementary tutoring

other

Search 350+ Subjects

Pre-Algebra : Circumference of a Circle

Study concepts, example questions & explanations for Pre-Algebra

All Pre-Algebra Resources

Example Questions

Example Question #1 : Circumference Of A Circle

Example Question #2 : Circumference Of A Circle

Example Question #1 : Circumference Of A Circle

Example Question #2 : Circumference Of A Circle

Example Question #1 : Know And Use The Formulas For The Area And Circumference Of A Circle: Ccss.Math.Content.7.G.B.4

Example Question #3 : Circumference Of A Circle

Example Question #4 : Circumference Of A Circle

Example Question #5 : Circumference Of A Circle

Example Question #6 : Circumference Of A Circle

Example Question #7 : Circumference Of A Circle

All Pre-Algebra Resources

Report an issue with this question

DMCA Complaint

Contact Information

Address

Complaint Details

Email address:
Your name:
Feedback: