Respuesta :

angrykai23

Answer:

Choice B. 29

Step-by-step explanation:

Use law of cosines:

[tex]a^2=b^2+c^2-bcCosA[/tex]

[tex]a=\sqrt{b^2+c^2 -bcCosA}[/tex]

[tex]a=\sqrt{19^2+12^2-(19)(12)Cos138}[/tex]

[tex]a=29.0495[/tex]