Elizabeth plays a snare drum. After measuring it, she calculates that it has a circumference of 113.04 centimeters. What is the drum's radius?

Use 3.14 for ​𝜋. If necessary, round your answer to the nearest hundredth.

1 answer

To find the radius of the drum from its circumference, we can use the formula for the circumference of a circle, which is:

\[ C = 2\pi r \]

where \( C \) is the circumference and \( r \) is the radius. We need to solve for \( r \):

\[ r = \frac{C}{2\pi} \]

Given that the circumference \( C = 113.04 \) cm and using \( \pi \approx 3.14 \), we can substitute into the formula:

\[ r = \frac{113.04}{2 \times 3.14} \]

Calculating the denominator:

\[ 2 \times 3.14 = 6.28 \]

Now, substitute this value back into the equation for \( r \):

\[ r = \frac{113.04}{6.28} \]

Next, we perform the division:

\[ r \approx 18.00 \]

Thus, the radius of the drum is approximately \( 18.00 \) centimeters when rounded to the nearest hundredth.