What is the length of AB¯¯¯¯¯?
Enter your answer as a decimal in the box. Round only your final answer to the nearest tenth.
We can use the Law of Cosines, here
AB^2 = 18^2 + 12^2 - 2 (18)(12)cos(79)
AB^2 = 324 + 144 - 432*cos(79)
AB^2 = 468 - 432*cos(79)
AB = √ [ 468 - 432*cos(79) ] ≈ 19.6
+309 
