+0  
 
0
83
1
avatar+54 

What is x to the nearest tenth?

 

A.37.5

 

B.52.5

 

C.75.0

 

D.103.0

 Mar 25, 2020
 #1
avatar+111321 
+1

We can use  the Law  of Cosines here

 

31^2  = 39^2  +  22^2 - 2 (39 * 22) cos (ABC)

 

Rearrange as

 

cos (ABC) =   [ 31^2 - 39^2  - 22^2 ]  / [ -2 * 39 * 22 ]    =  87 / 143

 

Taking  the inverse cosine

 

arccos  ( 87 / 143 )  ≈  52.5°   =  x

 

 

cool cool cool

 Mar 25, 2020

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