Find Missing Parallelogram Angles And Sides:

The answers should end up being a = 15 (given), b= 16.96, c = 25 (given), d = 20 (given), theta = 77.2 degrees, alpha = 102.8 degrees.

I am trying to find the two angles and side b. I used the Law of Cosines to try to find an angle, but no matter what combination of the 3 sides I use, I never get the correct answer.

Question

Find Missing Parallelogram Angles And Sides:

The answers should end up being a = 15 (given), b= 16.96, c = 25 (given), d = 20 (given), theta = 77.2 degrees, alpha = 102.8 degrees. 

I am trying to find the two angles and side b. I used the Law of Cosines to try to find an angle, but no matter what combination of the 3 sides I use, I never get the correct answer.

anonymous · Answer

attachment

ganeshie8 · Answer

im getting b = 42.72 http://www.wolframalpha.com/input/?i=sqrt%2820%5E2%2B25%5E2-2*20*25*cos%28143.13%29%29&a=TrigRD_D

ganeshie8 · Answer

are u getting the same ?

anonymous · Answer

you forgot to divided it by 2ac or 2ab

anonymous · Answer

I think?

ganeshie8 · Answer

ive checked, it looks ok to meh :) you may use this app to confirm ur work. looks the text book answers are wrong http://nayuki.eigenstate.org/page/triangle-solver-javascript

anonymous · Answer

I wish they were wrong, but there's no way they are.  Do you double the angle or something because theta and alpha include two corners of two triangles?

ganeshie8 · Answer

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