Find the Bearing from A to C & Angle B: Solve Here

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    Angle Bearing Point
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Discussion Overview

The discussion centers around determining the distance and bearing from point A to point C in a navigation problem involving an airplane's flight path. Participants are exploring the application of the law of cosines and the calculation of angles in a geometric context.

Discussion Character

  • Mathematical reasoning

Main Points Raised

  • One participant describes the flight path from A to B and then B to C, indicating the need to use the law of cosines to find the distance AC and the angle BAC.
  • Another participant provides a formula for calculating AC and suggests that the bearing can be found by adding the angle BAC to the initial bearing of 25 degrees.
  • A question is raised regarding the determination of angle ABC, specifically asking how it was calculated to be 165 degrees.

Areas of Agreement / Disagreement

Participants have not reached a consensus on the calculation of angle ABC, as one participant questions the method used to determine this angle.

Contextual Notes

The discussion involves assumptions about the angles and the application of trigonometric laws, which may depend on the definitions and conventions used for bearings and angles in navigation.

cbarker1
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Dear everyone,

An airplane flies 470 miles from point $A$ to point $B$ with a bearing of 25 degrees. It then flies from 250 miles from point $B$ to point $C$ with a bearing of 40 degrees. Find the distance and the bearing from A to point C.
Work

Bearing Problem.png

I understand that I need to use law of cosines for the side $b$ which is opposite of the angle $B$. But I have a hard time with find what is the angle $B$ is. I forgot many things from geometry. How to determine the angle from point $A$ to point $C$?

Thanks
Cbarker1
 
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$AC = \sqrt{470^2+250^2 - 2(470)(250)\cos(165)}$

bearing = $25^\circ + m\angle{BAC}$

$\angle{BAC}$ may be found using either the sine or cosine law
 
How did you determine the angle ABC to be 165?
 
bearings.jpg
 

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