Circumference and Area of a Circle

1. A circle has a circumference of $113.04$ units.

What is the diameter of the circle?

_______ units

2. A circle has a circumference of $452.16$ units.

What is the radius of the circle?

_______ units

3. What is the circumference of the following circle?

_______ units

4. Suppose the diameter of a circle is $16$ units. What is its circumference?

_______ units