[tex]x-the\ second\ angle\\\\x+17^o-the\ first\ angle\\\\6x-the\ third\ angle\\\\The\ equation:x+x+17^o+6x=180^o[/tex]
[tex]Solve:\\\\8x=180^o-17^o\\\\8x=163^o\ \ \ \ |divide\ both\ sides\ by\ 8\\\\x=\frac{163^o}{8}\\\\x=20.375^o\\\\x+17^o=20.375^o+17^o=37.375^o\\\\6x=6\times20.375^o=122.25^o\\\\Measure\ of\ the\ angles:37.375^o;\ 20.375^o\ and\ 122.25^o.[/tex]