Trig/geometry help (triangles/finding sides)

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SUMMARY

The discussion focuses on solving for side 'R' in a triangle where L = 6.10 meters, theta = 36.9 degrees, and phi = 53.1 degrees. Participants reference the Pythagorean Theorem, Law of Sines, and Law of Cosines as essential tools for the solution. A key insight involves drawing a vertical line through the triangle to establish relationships between the angles and sides, ultimately leading to the equation L/sin(phi + theta) = R/cos(phi) for calculating side 'R'.

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  • Understanding of the Pythagorean Theorem
  • Familiarity with the Law of Sines
  • Knowledge of the Law of Cosines
  • Basic concepts of trigonometry and triangle properties
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  • Study the application of the Law of Sines in non-right triangles
  • Explore the Law of Cosines for solving triangle side lengths
  • Practice problems involving the Pythagorean Theorem in various contexts
  • Learn how to construct and analyze geometric figures for trigonometric solutions
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Students studying trigonometry, educators teaching geometry, and anyone needing to solve problems involving triangle side lengths and angles.

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Homework Statement


h83RV.png

Find side 'R'. L = 6.10 meters, theta = 36.9 degrees, and phi = 53.1 degrees.

Homework Equations


Pythagorean Theorem
Similar triangles
Law of Sines
Law of Cosines

The Attempt at a Solution


I don't see any way I can attempt this, I'm very rusty with my trig. We have a known side and a right angle, but I don't see how I can make any other angles (since we only have one side I'm assuming I need to get an angle somewhere
 
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PhizKid said:

Homework Statement


h83RV.png

Find side 'R'. L = 6.10 meters, theta = 36.9 degrees, and phi = 53.1 degrees.

Homework Equations


Pythagorean Theorem
Similar triangles
Law of Sines
Law of Cosines

The Attempt at a Solution


I don't see any way I can attempt this, I'm very rusty with my trig. We have a known side and a right angle, but I don't see how I can make any other angles (since we only have one side I'm assuming I need to get an angle somewhere

Draw a vertical line through the right side of the length L (the point on the triangle). The length L will be perpendicular to this line, yes? And now take notice that \phi would be the angle between the vertical and the side of the triangle because of the parallel lines rule (the wall is parallel to the vertical line we constructed).
 
law of sines gives

L/sin(phi+theta)=R/cos(phi)
 

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