We are open Saturday and Sunday!

Call Now to Set Up Tutoring:

(888) 888-0446

GED Math : Area of a Circle

Study concepts, example questions & explanations for GED Math

Create An Account

All GED Math Resources

4 Diagnostic Tests 263 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #152 : Geometry And Graphs

Find the area of a circle given that it's circumference is $20\pi$ .

Possible Answers:

$10\pi$

$20\pi$

$100\pi$

$5\pi$

$1000\pi$

Correct answer:

$100\pi$

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

However, the problem doesn't give us radius. The only value provided is the circumference. The formula for circumference is $C = \pi d$ , where d is diameter. So what is the relationship between these two formulas? Since the diameter of a circle is twice the radius, we can see that the relationship helps us find r to solve for the area.

The circumference equation can be rewritten as $C= \pi \cdot 2r$

In order to solve for the radius, we must substitute in the circumference value provided. This will allow us to solve for r.

$20\pi = \pi \cdot 2r$

$\frac{20\pi}{2\pi}=r$

r=10

Now that we know that value of r, the area can be solved for.

$A = \pi (10^2)$

$A = 100\pi$

Report an Error

Example Question #153 : Geometry And Graphs

Find the area of a circle given that it's circumference is $14\pi$ .

Possible Answers:

$196\pi$

$7\pi$

$49\pi$

$2\pi$

$14\pi$

Correct answer:

$49\pi$

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

The circumference equation can be rewritten as $C= \pi \cdot 2r$

In order to solve for the radius, we must substitute in the circumference value provided. This will allow us to solve for r.

$14\pi = \pi \cdot 2r$

$\frac{14\pi}{2\pi}=r$

r=7

Now that we know that value of r, the area can be solved for.

$A = \pi (7^2)$

$A = 49\pi$

Report an Error

Example Question #154 : Geometry And Graphs

What is the area of a circle if it has a circumference of 37.68 ?

Possible Answers:

$12\pi$

$27\pi$

$37\pi$

$36\pi$

$4\pi$

Correct answer:

$36\pi$

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

The circumference equation can be rewritten as $C= \pi \cdot 2r$

In order to solve for the radius, we must substitute in the circumference value provided. This will allow us to solve for r.

$37.68 = \pi \cdot 2r$

$\frac{37.68}{2\pi}=r$

r=6

Now that we know that value of r, the area can be solved for.

$A = \pi (6^2)$

$A = 36\pi$

Report an Error

Example Question #155 : Geometry And Graphs

Find the area of a circle, given that it's diameter is 13.

Possible Answers:

$7.5\pi$

$42.5\pi$

$34.33\pi$

$56.25\pi$

$13\pi$

Correct answer:

$56.25\pi$

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

However, the problem doesn't give us a value for the radius. The only value provided is the diameter. The formula for diameter is d=2r , where d is diameter and r is radius. Using this relationship will help us find r so we can solve for the area.

13=2r

$\frac{13}{2}=r$

r=7.5

Now that we know that value of r, the area can be solved for.

$A = \pi (7.5^2)$

$A = 56.25\pi$

Report an Error

Example Question #61 : Area Of A Circle

What is the area of a circle if it has a diameter of ?

Possible Answers:

$144\pi$

$74\pi$

$24\pi$

$12\pi$

$36\pi$

Correct answer:

$144\pi$

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

24=2r

$\frac{24}{2}=r$

r=12

Now that we know that value of r, the area can be solved for.

$A = \pi (12^2)$

$A = 144\pi$

Report an Error

Example Question #62 : Area Of A Circle

Find the area of a circle that has a radius of meters.

Possible Answers:

$256\pi$ meters^2

$16\pi$ meters^2

$64\pi$ meters^2

$8\pi$ meters^2

$24\pi$ meters^2

Correct answer:

$256\pi$ meters^2

Explanation:

In order to find the area of a circle, we must know the formula that will give us the appropriate answer. The area of a circle is $A=\pi r^2$ , where r is the radius.

Since the problem provides the value of the radius, we just need to substitute in the value for r in order to solve for area

$A = \pi (16^2)$

$A = 256\pi$ meters^2

Report an Error

Example Question #163 : Geometry And Graphs

The diameter of a circle is . Find the area.

Possible Answers:

$10\Pi$

$25\Pi$

$5\Pi$

$100\Pi$

Correct answer:

$25\Pi$

Explanation:

The formula for the area of a circle is

$area = \Pi r^2$

with standing for radius.

In this problem, however, you are given the diameter, not the radius. You therefore need to solve for the radius first. This is simple. The diameter is twice the length of the radius, so if the diameter is , the radius is . (10 / 2 = 5) .

Once you have the radius, you can plug it into the formula for the area of a circle, and solve.

$\Pi r^2 = \Pi (5)^2 = 25\Pi$

So, the area of the circle is $25\Pi$ .

Report an Error

Example Question #164 : Geometry And Graphs

You and your friends are ordering pizza for your Friday night Mathathon. You decide to order three pizzas, each 16" in diameter. Find the area of each pizza to the nearest tenth.

Possible Answers:

A=603.2 in^2

A=201.1 in^2

A=804.2 in^2

A=401.1 in^2

Correct answer:

A=201.1 in^2

Explanation:

You and your friends are ordering pizza for your Friday night Mathathon. You decide to order three pizzas, each 16" in diameter. Find the area of each pizza to the nearest tenth.

First, let's convert our diameter to radius:

$r=\frac{d}{2}=\frac{16 in}{2}=8 in$

Next, use the following formula to solve for Area.

$A=\pi r^2= \pi (8in)^2=64 \pi in ^2 \approx 201.1 in^2$

So, our answer is:

A=201.1 in^2

Report an Error

Example Question #165 : Geometry And Graphs

A $90 ^{\circ }$ arc of a circle has length $7 \pi$ . Which expression gives its area?

Possible Answers:

196

$98 \pi$

$196 \pi$

Correct answer:

$196 \pi$

Explanation:

A $90 ^{\circ }$ arc of the circle is one fourth of the circle, so the length of the arc is

$L = \frac{1}{4}C$ ,

where is its circumference.

Since $L = 7 \pi$ , substitute as follows:

$\frac{1}{4}C = 7 \pi$

Multiply both sides by 4:

$\frac{1}{4}C \cdot 4 = 7 \pi \cdot 4$

$C = 28 \pi$

The radius of a circle is its circumference divided by $2 \pi$ , so

$r= \frac{C}{2\pi}$

$r= \frac{28 \pi }{2\pi} = 14$

Substitute this for in the formula

$A = \pi r^{2}$

to get

$A = \pi \cdot 14^{2} = \pi \cdot 14 \cdot 14 = 196 \pi$ ,

the correct choice.

Report an Error

Example Question #166 : Geometry And Graphs

Use 3.14 for pi and round your answer to the nearest hundredth.

Find the area of a circle with a diameter of 12cm.

Possible Answers:

113.04cm

$37.68cm^{2}$

452.16cm

$452.16cm^{2}$

$113.04cm^{2}$

Correct answer:

$113.04cm^{2}$

Explanation:

First we need to recall that the formula for area of a circle is

$Area=r^{2}\cdot \pi$

Where is radius and $\pi$ is 3.14

The circe we are working with has a diameter of 12. The diameter is twice the length of the radius, so to find the radius we cut it in half, and we get 6cm.

Now we can plug our radius and pi into our equation and solve for the area

$Area=(6cm)^{2}\cdot3.14$

Following order of operations, first we need to address the exponent. Any number to the second power (squared) is that number times itself one time (in this case it is 6x6)

$Area=36cm^{2}\cdot3.14$

Next we multiply

$Area=113.04cm^{2}$

Since we multiplied two terms whose units are in cm, our answer is in centimeters squared.

Report an Error

View Tutors

Joshua
Certified Tutor

Murray State University, Bachelor in Arts, Spanish. Lipscomb University, Bachelor of Science, Teacher Assistant.

View Tutors

Kaylee
Certified Tutor

Brigham Young University, Bachelor, MFA - Animation.

View Tutors

Lydia
Certified Tutor

The Richard Stockton College of New Jersey, Bachelor of Science, Biochemistry and Molecular Biology.

All GED Math Resources

4 Diagnostic Tests 263 Practice Tests Question of the Day Flashcards Learn by Concept

Popular Subjects

GMAT Tutors in Atlanta, SSAT Tutors in Denver, MCAT Tutors in Philadelphia, Physics Tutors in San Francisco-Bay Area, Reading Tutors in New York City, Biology Tutors in Houston, Statistics Tutors in Miami, English Tutors in Boston, Physics Tutors in Houston, Spanish Tutors in Philadelphia

Popular Courses & Classes

ISEE Courses & Classes in Boston, Spanish Courses & Classes in Seattle, GRE Courses & Classes in San Francisco-Bay Area, LSAT Courses & Classes in Boston, SAT Courses & Classes in San Francisco-Bay Area, Spanish Courses & Classes in Atlanta, ISEE Courses & Classes in Houston, ACT Courses & Classes in New York City, LSAT Courses & Classes in San Diego, GRE Courses & Classes in New York City

Popular Test Prep

GMAT Test Prep in Phoenix, SSAT Test Prep in Seattle, SAT Test Prep in Phoenix, MCAT Test Prep in Los Angeles, SSAT Test Prep in Denver, GRE Test Prep in Chicago, GMAT Test Prep in Philadelphia, MCAT Test Prep in Seattle, SAT Test Prep in Boston, ACT Test Prep in Seattle

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

GED Math : Area of a Circle

Study concepts, example questions & explanations for GED Math

All GED Math Resources

Example Questions

Example Question #152 : Geometry And Graphs

Example Question #153 : Geometry And Graphs

Example Question #154 : Geometry And Graphs

Example Question #155 : Geometry And Graphs

Example Question #61 : Area Of A Circle

Example Question #62 : Area Of A Circle

Example Question #163 : Geometry And Graphs

Example Question #164 : Geometry And Graphs

Example Question #165 : Geometry And Graphs

Example Question #166 : Geometry And Graphs

All GED Math Resources

Report an issue with this question

DMCA Complaint

Contact Information

Address

Complaint Details

Email address:
Your name:
Feedback: