Question

find the circumference of a circle with radius 11.8 in., both in terms of π and to the nearest tenth. use 3.14 for π. ○ c = 139.24π in. ≈ 437.2 in. ○ c = 11.8π in. ≈ 37.1 in. ○ c = 23.6π in. ≈ 74.1 in. ○ c = 5.9π in. ≈ 18.5 in.

Explanation:

Step1: Recall the formula for the circumference of a circle

The formula for the circumference \( C \) of a circle is \( C = 2\pi r \), where \( r \) is the radius of the circle.

Step2: Calculate the circumference in terms of \( \pi \)

Given that the radius \( r = 11.8 \) in. Substitute \( r \) into the formula:
\( C = 2\pi\times11.8 = 23.6\pi \) in.

Step3: Calculate the numerical value using \( \pi = 3.14 \)

Substitute \( \pi = 3.14 \) into \( C = 23.6\pi \):
\( C = 23.6\times3.14 \)
First, calculate \( 23\times3.14 = 72.22 \) and \( 0.6\times3.14 = 1.884 \)
Then, add them together: \( 72.22 + 1.884 = 74.104 \)

Step4: Round to the nearest tenth

\( 74.104 \) rounded to the nearest tenth is \( 74.1 \)

Answer:

C = 23.6π in. ≈ 74.1 in. (the third option)