A satellite S is in a geosynchronous orbit; that is, it stays over the same point T on Earth as Earth rotates on its axis. From the satellite, a spherical cap of Earth is visible. The circle bounding this cap is called the horizon circle. The line of sight from the satellite is tangent to a point Q on the surface of Earth. If the radius of Earth, CQ, is 3963 miles and the satellite is 23300 miles form the surface of the Earth at Q, what is the radius of the horizon circle, PQ, in miles?
I've been staring at this problem for hours. I'm completely stumped.