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What is the arc length?

What is the arc length?-example-1
User Jean Costa
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2 Answers

7 votes

Answer:

Explanation:

You could do this one of 2 ways. I'll show you both ways and you decide which one works best for you to use on your own.

First, by using the circumference formula of a circle.

C = 2πr and we know the radius is 5, so the circumference of the circle is

C = 10π

1/4 of the circle is missing, so 10π/4 gives you the length of the arc that is missing.


(10\pi)/(4)=2.5\pi

10π - 2.5π = 7.5π

OR we could do the problem using the formula for the arc length which is


AL=(\theta)/(360)*2πr

The measure of the angle shown is for the missing part of the circle. If the measure of a circle is 360, and the measure of the angle for the part of the circle that's missing is 90, then 360 - 90 is the measure of the central angle of the part of the circle that's still there. So the measure of theta is 270°.


AL=(270)/(360)*10\pi and simplifying a bit:


AL=.75(10\pi) so the arc length is

AL = 7.5π

Use either way. They both work.

User KidA
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7.4k points
3 votes

do you have a picture for the question?

User Walter Johnson
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8.0k points