PSAT Math : How to find the angle of a sector

Study concepts, example questions & explanations for PSAT Math

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Example Questions

Example Question #21 : Circles

What is the angle of a sector that has an arc length of   on a circle of diameter  ?

Possible Answers:

Correct answer:

Explanation:

The first thing to do for this problem is to compute the total circumference of the circle. Notice that you were given the diameter. The proper equation is therefore:

For your data, this means,

Now, to compute the angle, note that you have a percentage of the total circumference, based upon your arc length:

Rounded to the nearest hundredth, this is .

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