Trigonometry (11th Edition) Clone

Let $R$ be the Earth's radius. We can use the Pythagorean theorem to find $h$: $(R+h)^2 = R^2+(125~mi)^2$ $R+h = \sqrt{R^2+(125~mi)^2}$ $h = \sqrt{R^2+(125~mi)^2}-R$ $h = \sqrt{(4.00\times 10^3~mi)^2+(125~mi)^2}-(4.00\times 10^3~mi)$ $h = 1.95~mi$ The minimum height is 1.95 miles.