All SAT II Math II Resources
Example Questions
Example Question #31 : 2 Dimensional Geometry
If a particle accelerator has a circumference of , what is its radius?
If a particle accelerator has a circumference of , what is its radius?
Begin with the formula for the circumference of a circle:
Now, we know the circumference, so just plug in and solve for r.
Divide both sides by 2 pi to get out answer:
Example Question #1 : Diameter, Radius, And Circumference
If a particle accelerator has a circumference of , what is its diameter?
If a particle accelerator has a circumference of , what is its radius?
Begin with the formula for circumference of a circle:
Now, we can see that 2r is really the same as d, right? Our radius will always be half the length of the diameter.
So, we can rewrite the above equation as:
Now, plug in our circumference and solve for d:
Divide both sides by pi to get:
So our answer is 18.5 miles
Example Question #1 : Diameter, Radius, And Circumference
If the circumference of a circle is , what must be the diameter?
Write the circumference formula for the circle.
Substitute the circumference into the equation.
Divide by on both sides.
The diameter is twice the radius.
The answer is:
Example Question #2 : Diameter, Radius, And Circumference
What is the circumference of a circle with a diameter of ?
Write the formula for the circumference of a circle.
Substitute the diameter into the equation.
The answer is:
Example Question #2 : Diameter, Radius, And Circumference
What is the diameter of the circle with a radius of ?
The diameter of a circle is twice the radius.
Substitute the radius.
The answer is:
Example Question #3 : Diameter, Radius, And Circumference
Determine the radius if the circumference of a circle is .
Write the formula for the circumference of a circle.
Substitute the circumference.
Divide by on both sides.
Reduce both sides.
The answer is:
Example Question #3 : Diameter, Radius, And Circumference
Determine the radius of a circle if the circumference is .
Write the formula for the circumference of a circle.
Substitute the circumference.
Multiply by on both sides to isolate .
The radius is:
Example Question #2 : Diameter, Radius, And Circumference
Determine the diameter if the radius of a circle is .
The diameter is double the radius. Multiply the radius by two.
The answer is:
Example Question #3 : Diameter, Radius, And Circumference
Determine the circumference of a circle with a radius of .
The circumference of a circle is:
Substitute the radius.
The answer is: