A merry-go-round has a radius of 10 ft. To the nearest tenth of a foot, what distance does the merry-go-round cover when it rotates through an angle of 72°?

For my first try, I got 62.9 as my answer, and it was marked wrong. I did this a second time, and got 12.6. I would like to check with anyone else to see if I got the answer right.

The answers for this question were:

62.9, 12.6, 25.1, or 125.7

Question

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Mathematics

10 December, 11:13

A merry-go-round has a radius of 10 ft. To the nearest tenth of a foot, what distance does the merry-go-round cover when it rotates through an angle of 72°?

For my first try, I got 62.9 as my answer, and it was marked wrong. I did this a second time, and got 12.6. I would like to check with anyone else to see if I got the answer right.

The answers for this question were:

62.9, 12.6, 25.1, or 125.7

+5

Answers (1)

Know the Answer?

Shyann Boyle · Answer 1

Yes, the correct answer is 12.6 ft.

Using the formula of arc length, that is

s = rθ

where s = arc length, r = radius, θ = angle (unit must be in radian)

With r = 10 ft and θ = 72 deg (π/180 deg) = 1.26 rad,

s = (10) (1.26) = 12.6 ft