Find Side Lengths of an Isosceles Triangle

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Homework Help Overview

The problem involves finding the lengths of the sides of an isosceles triangle given two equal sides and a perimeter. The sides are specified as A=97.433, B=41.283, and C=41.283, with a total perimeter of 24.78 inches.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the possibility of using ratios of side lengths in conjunction with the perimeter to find the individual side lengths. There is uncertainty about the applicability of the law of cosines and the law of sines, with questions about how to incorporate the perimeter into the solution.

Discussion Status

The discussion is ongoing, with participants exploring various equations related to the triangle's properties. Some have noted the presence of multiple equations but question their independence and how they relate to the given perimeter.

Contextual Notes

Participants express confusion regarding the application of the laws of sines and cosines, and there is a lack of clarity on how to effectively use the perimeter in their calculations. The original poster mentions that this type of triangle was not covered in their geometry class.

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Homework Statement


All three sides of an isoceles triangle are given along with its perimeter. Find the length of each side.
A=97.433 B=41.283 C=41.283
Perimeter=24.78in

Homework Equations


p = a+b+c
a2=b2+c2 - 2*b*c*cos(A)


The Attempt at a Solution


Would you somehow find the ratios of the side lengths? And then use the ratios and the perimeter to find the sides? I don't even know if this is possible. We definitely never did these kinds of triangles in geometry class. Thanks for any help :)
 
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I see you listed the law of cosines in the equations... but forgot the law of sines...
 
Law of sines: c/sin(A) = c/sin(B) = c/sin(C)

Do I have to solve this as a system of equations to solve for the sides? But where does the given perimeter come into play?
 
You have many equations:
a+ b+ c= 24.78
b= c
c^2= a^2+ b^2- 2abcos(41.283)
b^2= a^2+ c^2- 2accos(41.283)
a^2= b^2+ c^2- 2bccos(97.433)
\frac{a}{sin(97.433)}= \frac{b}{sin(41.283)}
\frac{a}{sin(97.433)}= \frac{c}{sin(41.283)}
\frac{b}{sin(41.283)}= \frac{c}{sin(41.283)}
Of course, these are not all independent.
 

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