Circumference and Area of Circles - 
Exact values using pi.

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Answers should be in terms of pi.  Use lower case pi in the answer.  Example: 42pi or 6.25pi 

1.   

The diameter of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

2.   

The radius of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

3.   

The diameter of the circle is  units
The radius of the circle is  units
The area of the circle is  square units

4.   

The diameter of the circle is  units
The radius of the circle is  units
The circumference of the circle is   units

5.   

The diameter of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

6.   

The radius of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

7.   

The diameter of the circle is  units
The radius of the circle is  units
The area of the circle is  square units

8.   

The diameter of the circle is  units
The radius of the circle is  units
The circumference of the circle is   units

9.   

The diameter of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

10.   

The radius of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units

Go to Approximate Measures Page

More information

The radius of a circle is the distance from the center to a point on the circle.
The diameter of a circle is the distance from one point on the circle, through the center, and to a point on the other side of the circle.
The measure of a diameter is twice the measure of the radius.
The circumference of a circle is it's perimeter.  The circumference is equal to the diameter times pi (approximately 3.14).
The area of a circle is equal to the square of the radius times pi.
Note that the circumference is a measure of distance and is in units.  The area is measured in square units.

Example:

 

The diameter of the circle is  units
The circumference of the circle is  units
The area of the circle is  square units