Question

A circle has a radius of 3
inches and an area of 9π
square inches.

Which expression should be used to find the circumference of this circle?

Responses

9π3⋅2
9π3⋅2

9π3
9π3

9π⋅(3)2
9π⋅(3)2

9π2⋅3

Answer 1

To find the circumference of a circle, you can use the formula:

\[ C = 2\pi r \]

where \( r \) is the radius of the circle.

In this case, the radius of the circle is 3 inches, so the circumference can be calculated using:

\[ C = 2\pi(3) \]

The expressions provided for finding the circumference can be simplified by substituting \( r = 3 \):

- 9π3⋅2 (This equals \( 2\pi(3) \), which is correct)
- 9π3 (This is not the correct form for circumference)
- 9π⋅(3)2 (This seems to imply squaring the radius, which is not correct)
- 9π2⋅3 (This is not the correct form for circumference)

The correct expression among the provided options that can represent the circumference calculation is:

**9π3⋅2**

So this expression should be used to find the circumference of the circle.