Refer to the diagram shown below.
x = the distance (horizon) that you can see from the balloon,
Because the radius of the earth is 6400 km, and the balloon is 350 n above the earth's surface, therefore
h = 6400 + 0.350 = 6400.35 km.
From the Pythagorean theorem, obtain
x = √(6400.35² - 6400²) = 66.934 km
Answer: Your horizon is 66.934 km (or 66,934 m)
