[tex]1)\ on remarque\ que\ 5^2+12^2=25+144=169=13^2 \\
alors\ EF^2+FG^2=EG^2.\ D'apres\ la\ reciproque\ de\ th\acute{e}oreme\ de\\
Pythagore\ le\ triangle\EFG\ est\ rectangle\ en\ F\\
2)\ \frac{FE}{EG}= \sin(\widehat(FGE))= \frac{12}{13} ==\ \textgreater \ mes\ \widehat(FGE) =sin^{-1} ( \frac{12}{13})\\
\frac{FG}{EG}= sin(FEG)= \frac{5}{13}==\ \textgreater \ mes\ FEG = sin^{-1}( \frac{5}{13}) [/tex]