anonymous 5 years ago Assume the radius of Earth is 3960 miles and that there areno hills or obstructions. About how far can you see to the horizon from an airplane 5 miles high?

1. anonymous

Your line of sight from the plane forms a tangent with Earth (the horizon), this gives you a right-angled triangle with sides of length 3960m and 3960+5=3965m. Using Pythagoras' theorem give the other side as:$\sqrt{3965^2-3960^2}\approx199m$

2. anonymous

thanks.

3. anonymous

No problem.