Question
What is the radius of this circle if the circumference is 18 pi cm?
Answers
GPT-4o mini
The formula for the circumference \( C \) of a circle is given by:
\[
C = 2\pi r
\]
where \( r \) is the radius of the circle. Given that the circumference \( C = 18\pi \) cm, we can set up the equation:
\[
2\pi r = 18\pi
\]
Next, we divide both sides of the equation by \( 2\pi \):
\[
r = \frac{18\pi}{2\pi}
\]
Simplifying the right side, we get:
\[
r = \frac{18}{2} = 9
\]
Thus, the radius of the circle is:
\[
\boxed{9 \text{ cm}}
\]
\[
C = 2\pi r
\]
where \( r \) is the radius of the circle. Given that the circumference \( C = 18\pi \) cm, we can set up the equation:
\[
2\pi r = 18\pi
\]
Next, we divide both sides of the equation by \( 2\pi \):
\[
r = \frac{18\pi}{2\pi}
\]
Simplifying the right side, we get:
\[
r = \frac{18}{2} = 9
\]
Thus, the radius of the circle is:
\[
\boxed{9 \text{ cm}}
\]