3.7.3 Quiz: Circumference of a Circle

Question 1 of 10

A CD is shaped like a circle with a diameter of 12 cm. To the nearest centimeter, what is the circumference of the CD?

A. 19 cm
B. 38 cm
C. 75 cm
D. 24 cm



Answer :

To find the circumference of a circle, we use the formula:
[tex]\[ C = \pi \times d \][/tex]

where [tex]\( C \)[/tex] is the circumference and [tex]\( d \)[/tex] is the diameter of the circle.

Given:
- The diameter ([tex]\( d \)[/tex]) of the CD is 12 cm.

Let's plug the diameter into the formula:
[tex]\[ C = \pi \times 12 \][/tex]

Using the value of [tex]\(\pi \)[/tex] (approximately 3.14159), we can calculate:
[tex]\[ C = 3.14159 \times 12 \][/tex]

This multiplication gives the circumference:
[tex]\[ C \approx 37.69908 \][/tex]

To the nearest centimeter, we round this result:
[tex]\[ 37.69908 \approx 38 \][/tex]

Thus, the circumference of the CD, rounded to the nearest centimeter, is:
[tex]\[ \boxed{38 \text{ cm}} \][/tex]

So, the correct answer to the question is:
B. 38 cm