All GED Math Resources
Example Questions
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 #118 : 2 Dimensional Geometry
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 #119 : 2 Dimensional Geometry
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 #123 : 2 Dimensional Geometry
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:
Example Question #126 : 2 Dimensional Geometry
Find the area of the circle with radius of .
Write the formula for the area of a circle.
Substitute the radius.
The answer is: