You're in an airplane 5.7 miles above the ground. What is the measure of BD, The portion of earth that you can see? Round your answer to the nearest 10th. (earths radius is approximately 4000 miles)
You should have a picture of your question.
You can find the distance to the Horizon, using this formula:
D = Sqrt[2 x 5.7 miles x 4000 miles] =213.54 miles - distance from the plane to the horizon.
You can use this as the RADIUS of a sphere and calculate whatever you want. Your question is very vague !.