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 Question from Wallis, a student: I have more then a quarter of a circle, but less than half. What is the circumference if the two side are 7cm and the angle between them is 110 degrees?

Hi Wallis,

The circumference of a circle is 2 r where r is the radius. Thus your circle has a circumference of

2 7 = 14 centimeters.

But, as you said, the sector you have is more than a quarter of this but less than half. Since all the way around the circle is 360 degrees the fraction of the circle you have is 110/360. Thus the length of your arc is

110/360 14 centimeters.

Penny

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