All GED Math Resources
Example Questions
Example Question #115 : 2 Dimensional Geometry
If the diameter of circle is , what must be the area?
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 #116 : 2 Dimensional Geometry
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.
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 #117 : 2 Dimensional Geometry
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.
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 #21 : Area Of A Circle
Find the area of a circle with a radius of 8in.
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 #22 : Area Of A Circle
Determine the area of a circle with an diameter of .
Write the formula for the area of a circle.
The radius is half the diameter.
The answer is:
Example Question #121 : 2 Dimensional Geometry
Find the area of a circle with a diameter of .
Write the formula for the area of a circle.
The radius is half the diameter.
Multiply the diameter by .
Substitute the radius.
The answer is:
Example Question #122 : 2 Dimensional Geometry
Find the area of a circle with a diameter of .
Write the area of a circle.
The radius is half the diameter.
Substitute the radius into the equation.
The answer is:
Example Question #21 : Area Of A Circle
Give the area of the above circle.
The area of a circle, given its radius , can be found using the formula
The radius is half the diameter - that is, - so, substituting,
or
The diameter of the given circle is 7, so set in the above formula:
,
the correct area.
Example Question #124 : 2 Dimensional Geometry
Let .
Find the area of a circle with a diameter of 12in.
To find the area of a circle, we will use the following formula:
where r is the radius of the circle.
Now, we know . We also know the diameter is 12in. We know the diameter is two times the radius, so the radius is 6in. Now, we can substitute. We get
Example Question #121 : Circles
What is the area of a circle with a circumference of ?
Write the formula for the area of a circle.
We will need to find the radius of the circle.
Write the formula for the circumference.
Substitute the circumference.
Divide by on both sides.
The radius is:
Substitute this into the area formula.
The answer is:
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