by Fredfredburger » Thu Mar 14, 2013 1:33 am
8E-60
Things to notice off the bat, 747 is your radius, and also the length of the equilateral triangle sides.
The area of your sector is some ratio, r, of the area of the entire circle. It is also that same ratio of degrees to the full circles 360 degrees. Find r
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Find how many degrees that the sector is.
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The angles of the two isosceles and the equilateral triangle then must constitute the rest of the 360 degrees. Since you know the measure of the equilateral, 60 degrees, you can find the measure of the other angle.
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Your obtuse angle in that isosceles is thus
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Now use the law of cosines to find your long side D.
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Now to find the length you're looking for just subtract the length of the equilateral triangle and you're good.
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MIT '17