Question

lesson 6: circles
changes in dimensions
if the diameter of a circle with a circumference of 18.84 inches were tripled, what would be the circumference of the new circle?
a. 6.28 in
b. 37.68 in
c. 18.84 in
d. 56.52 in
check answer

Explanation:

Step1: Recall the formula for circumference

The formula for the circumference of a circle is $C = \pi d$, where $C$ is the circumference and $d$ is the diameter.

Step2: Analyze the relationship between circumferences

If the diameter $d$ is tripled, the new diameter is $d_{new}=3d$. The new - circumference $C_{new}=\pi d_{new}=\pi(3d) = 3(\pi d)$. Since the original circumference $C=\pi d = 18.84$ inches, the new circumference $C_{new}=3\times18.84 = 56.52$ inches.

Answer:

D. 56.52 in