Answer:
C
Step-by-step explanation:
Using the cosine rule
cosZ = [tex]\frac{7^2+8^2-6^2}{2(7)(8)}[/tex] = [tex]\frac{49+64-36}{112}[/tex] = [tex]\frac{77}{112}[/tex] , thus
Z = [tex]cos^{-1}[/tex] ([tex]\frac{77}{112}[/tex] ) ≈ 47° ( to the nearest degree ) → C