Answer:
correct answer is option second
Step-by-step explanation:
We can apply law of cosines in triangle given in option 2 to determine third side
in this triangle two sides are given as 8 and 12
By applying law of cosines in triangle given in option 2
[tex]x^2 = 8^2 + 12^2-2\times 8\times 12cos(138)[/tex]...................(1)
by solving equatin 1 we can determine value of x so option 2 triangle can be use for applying law of cosines to determine for a missing side x
