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Course: Staging content lifeboat > Unit 8

Lesson 2: Trigonometry general triangles
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Staging content lifeboat
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Trigonometry general triangles
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GRAVEYARD Trig: Trigonometry with general triangles

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Problem

Amr is surveying a triangular plot of land. His end goal is to calculate the area of the plot, but first he needs to find one of the angles.
Amr starts by measuring all three sides of the plot: 87, 76, and 60 meters. With this information, he is able to calculate the measure of the angle opposite the 60 meter side.
What is the result of Amr's calculation in radians?
  • Your answer should be
  • an integer, like 6
  • an exact decimal, like 0.75
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
radians
Round your answer to the nearest hundredth.