Answer:
Arc BD is 6.1 degrees
Step-by-step explanation:
So if 5.7 is in miles, the observer is 30096 feet above sea level, cruising height.
Solution.
Segment BC and DC are tangent to the circle,
so angles CBA and CDA are 90 degrees, hence
Triangles CBA and CDA are right triangles,
with
AC = 4005.7 miles
cos CAB = AB/AC = 4000/4005.7 = 0.9985770
angle BCA = arc cos(0.9985770) = 3.057 degrees
Arc BD = central angle BAD = 2*angle BCA = 6.114 degrees
