+0  
 
+1
90
2
avatar+293 

need help asap please

 Nov 24, 2020
 #1
avatar
+2

Follow the instructions on this page:  https://www.mathsisfun.com/algebra/trig-cosine-law.html

 Nov 24, 2020
 #2
avatar+116126 
+2

Law of Cosines

 

x^2  = b^2  + c^2  - 2(b)(c)cos( CAB)

 

x^2  = 15^2 + 17^2  - 2(15)(17)cos (108°)

 

x^2  =  225 + 289  - 2 (255)cos(108°)

 

x^2  = 514 - 510cos(108°)

 

x = sqrt  [  514 - 510 cos(108°) ]  ≈    25.9

 

 

cool cool cool

 Nov 24, 2020
edited by CPhill  Nov 24, 2020

80 Online Users

avatar