[tex]\Large\boxed{\begin{array}{l}\underline{\boldsymbol{Observe~a~figura~que~eu~anexei.}}\\\\\underline{\rm Pela~lei~dos~cossenos~podemos~escrever:}\\\red{\tt x^2}=\blue{\tt (3\sqrt{2})^2+7^2}\\\red{\tt x^2}=\blue{\tt18+49}\\\red{\tt x^2}=\blue{\tt67}\\\red{\tt x=\sqrt{67}~cm}\end{array}}[/tex]
