Question

A circle has a radius of 5 in. A central angle that measures 150° cuts off an arc.
Explain how to find the arc length exactly, and then approximate it to one decimal place.​

Answer 1

Answer:

Part 1) The exact value of the arc length is $\frac{25}{6}\pi \ in$

Part 2) The approximate value of the arc length is $13.1\ in$

Step-by-step explanation:

step 1

Find the circumference of the circle

The circumference of a circle is equal to

$C=2\pi r$

we have

$r=5\ in$

substitute

$C=2\pi (5)$

$C=10\pi\ in$

step 2

Find the exact value of the arc length by a central angle of 150 degrees

Remember that the circumference of a circle subtends a central angle of 360 degrees

by proportion

$\frac{10\pi}{360} =\frac{x}{150}\\ \\x=10\pi *150/360\\ \\x=\frac{25}{6}\pi \ in$

step 3

Find the approximate value of the arc length

To find the approximate value, assume

$\pi =3.14$

substitute

$\frac{25}{6}(3.14)=13.1\ in$

Answer 2

Answer:

13.1 (rounded to tenths)

Step-by-step explanation:

150 ° into radian is 5/6.

150°/1 (π/180) =5π/6.

Then multiply the radian angle by the radius.

5π/6 (5) = 25π/6

25π/6 = 13.1 (rounded to tenths)