Answer:
196 km
Explanation:
See attached figure
The skydiver is at a height of 3 km above the earth surface at point S
Point H represents the horizon as seen by the skydiver
CH represents the radius of the earth = 6400
SH is the line of sight from S to H and is tangential to the circle representing the earth's surface
Sine SH is tangent to the circle, CH is perpendicular to SH
Therefore the triangle CSH is a right triangle with m∠H = 90°
The hypotenuse of the triangle is CS = 6400 + 3 = 6403 km
The legs are CH = 6400 and SH which is to be determined
Using the Pythagorean theorem
CS² = CH² + SH²
Plugging in knowns:
6403² = 6400² + SH²
SH² = 6403² - 6400² = 38409
SH = √(38409) ≈ 195.98 km ≈ 196 km rounded to nearest km