a weather satellite is traveling in a circular orbit 9800 miles above the surface of the earth. find the angle of depression from the satellite to the horizon. assume the radius of the earth is 4000 miles.

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i don't get how to find it. i tried finding the angle of angle 1 by using sin. did arcsin and got an angle of 16.85, subtracted it from 90 and got 73 degrees. i thought that was the angle of depression but the book says the answer is 15.5 degrees.