SOLUTION: A farmer has a triangular shaped field, FLD. DF-350m, FL= 240m and DL=400m. Calculate the angle to the nearest degree.

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Question 993872: A farmer has a triangular shaped field, FLD. DF-350m, FL= 240m and DL=400m. Calculate the angle to the nearest degree.
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) (Show Source):
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A farmer has a triangular shaped field, FLD. DF-350m, FL= 240m and DL=400m. Calculate the angle to the nearest degree.
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There are 3 angles. Angle F is opposite the longest side.
Use the Cosine Law:
400^2 = 350^2 + 240^2 - 350*240*cos(F)

Answer by ikleyn(52794) (Show Source):
You can put this solution on YOUR website!
.
A farmer has a triangular shaped field, FLD. DF-350m, FL= 240m and DL=400m. Calculate the angle to the nearest degree.
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There are 3 angles. Angle F is opposite the longest side.
Use the Cosine Law:
400^2 = 350^2 + 240^2 - 2*350*240*cos(F).

I got m(LF) =~ 83� (approximately).

For the Cosine Law see, for example, the lesson Proof of the Law of Cosines revisited in this site.