Question 1150168
An airplane is heading north at an airspeed of 750 km/hr, but there is a wind blowing from the northwest at 70 km/hr. 
The plane will end up flying 
(answer) degrees off course
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It's not necessarily "off course" as no course was stated.
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to find the ground track:
It's a triangle.
One side is on the y-axis from (0,0) to (750,0)
The 2nd side is from (750,0) at an interior angle 45 degs and length of 70.
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The groundspeed is the 3rd side.
Use the Cosine Law.
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Use the Law of Sines to find the angle at (0,0).