Question 1008689
A pilot flies in a straight path for 1 hour and 30 min. She then makes a course correction, heading 10 degrees to the right of her original course, and flies 2 hours in the new direction. If she maintains a constant speed of 625 miles per hour, how far is she from her starting position?

I found an answer but it was wrong, I would appreciate if you could point out the mistake.

convert hours into miles

(1.30Hrs * 625miles) / 1hr = 812.5 miles
(2 hrs * 625 miles) / 1hr = 1250 miles

Use Law of cosine to find missing side

A^2=B^2+c^2-2BC(cosA)
A^2=812.5^2+1250^2-2(812.5)(1250)cos10
A^2=222265...
A=sqrt(222265)= 471.45
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It's not cos(10).  The interior angle is 170 degs.