An airplane flies 180 miles from point A in the direction 135° and then travels in the direction 240° for 90 miles. Approximately how far is the airplane from A? (Round your answer to the nearest whole number.)

Answer 1

according to my quick sketch you have to use the cosine law
x^2 = 180^2 + 90^2 - 2(180)(90)cos 75°
...
x = appr 179 miles

Answer 2

Where did you get the 75 degrees from

Answer 3

Can somebody explain where the 75 came from please?