GED Math : Circles

Study concepts, example questions & explanations for GED Math

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Example Questions

Example Question #111 : 2 Dimensional Geometry

Determine the area of a circle with a radius of 15.

Possible Answers:

Correct answer:

Explanation:

Write the formula for the area of a circle.

Substitute the radius into the equation.

The answer is:  

Example Question #1072 : Ged Math

Determine the area of a circle if the radius is .

Possible Answers:

Correct answer:

Explanation:

Write the formula for the area of a circle.

Substitute the radius into the equation.

The answer is:  

Example Question #12 : Area Of A Circle

Determine the area of a circle in square feet with a radius of 12 inches.

Possible Answers:

Correct answer:

Explanation:

Write the formula for the area of a circle.

Convert the radius to feet.  There are 12 inches in a foot.

This means the radius in feet is 1.

Substitute the radius in feet to obtain the area in feet squared.

The answer is:  

Example Question #13 : Area Of A Circle

Find the area of a circle with a diameter of 26cm.

Possible Answers:

Correct answer:

Explanation:

To find the area of a circle, we will use the following formula:

where r is the radius of the circle.

Now, we know the diameter of the circle is 26cm. We also know the diameter is two times the radius. Therefore, the radius is 13cm.

So, we can substitute. We get

Example Question #14 : Area Of A Circle

Find the area of a circle with a radius of 12in.

Possible Answers:

Correct answer:

Explanation:

To find the area of a circle, we will use the following formula:

where r is the radius of the circle.

Now, we know the radius of the circle is 12in. So, we can substitute. We get

Example Question #15 : Area Of A Circle

If the diameter of circle is , what must be the area?

Possible Answers:

Correct answer:

Explanation:

Convert the mixed fraction to an improper fraction by multiplying the denominator with the whole number and adding the numerator.  The denominator stays constant.

Write the formula for the area of a circle.

The radius is half the diameter.

The answer is:  

Example Question #21 : Area Of A Circle

Sector40

The figure above is a circle.

If the radius of the circle above is 9 in., what is the area of the sector? Round to the nearest hundredth.

Possible Answers:

 

 

 

 

 

Correct answer:

 

Explanation:

To find the area of a sector, you are looking for a percentage of the total circle's area.  Thus, if the angle is  degrees, you are looking for  of a complete circle. 

Given that the radius is  in., you know that the area must be:

The area of the sector is:

or

Example Question #22 : Area Of A Circle

Sector77

The figure above is a circle.

If the diameter of the circle above is 10 in., what is the area of the sector? Round to the nearest hundredth.

Possible Answers:

 

 

 

 

 

Correct answer:

 

Explanation:

To find the area of a sector, you are looking for a percentage of the total circle's area.  Thus, if the angle is  degrees, you are looking for  of a complete circle. 

Given that the diameter is  in., you know that the radius is  in.  This means that the area must be:

The area of the sector is:

or

Example Question #23 : Area Of A Circle

Find the area of a circle with a radius of 8in.

Possible Answers:

Correct answer:

Explanation:

To find the area of a circle, we will use the following formula:

where r is the radius of the circle. 

Now, we know the radius of the circle is 8in. So, we can substitute. We get

Example Question #24 : Area Of A Circle

Determine the area of a circle with an diameter of .

Possible Answers:

Correct answer:

Explanation:

Write the formula for the area of a circle.

The radius is half the diameter.

The answer is:  

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