Respuesta :

[tex]cos~C= \frac{a^2+b^2-c^2}{2ab} \Leftrightarrow \frac{1}{2}= \frac{64+36-c ^{2} }{2*48} \Rightarrow 100-c^2=48 \Rightarrow c^{2}=52 \Rightarrow \\ c=2 \sqrt{13}.~~~~~(Cosinus~formula) \\ \\ cos~A= \frac{b^2+c^2-a^2}{2bc}= \frac{36+52-64}{24 \sqrt{13} } = \frac{24}{24 \sqrt{13} }= \frac{ \sqrt{13} }{13}. \\ \\ cos~A= \frac{ \sqrt{13} }{13} \Rightarrow m(\ \textless \ A) =74 \textdegree. [/tex]