Assuming that the earth is a perfect sphere, in units of the earth's radius, how high must one be to see
exactly one half of the earth's surface?
Okay... okay... how about exactly one third of the earth's surface?
Draw a semicircle of radius 3, center at 0,0. A tangent line from the circle at y=1 intersects at 0,9 giving the distance = 2r.

Posted by CeeAnne
on 20041006 10:59:14 