Refer to the diagram shown below.
The angle at DC (Washington, DC) is 90 + 55 =Β 145Β°.
Let d =Β the total distance traveled.
From the Law of Cosines, obtain
dΒ² = 5600Β² + 900Β² - 2(5600)(900) cos(145Β°)
Β Β Β = 4.0427 x 10β·
d = 6358.23 km
Answer: 6358.2 km (nearest tenth)