2π radians is 360 degrees.
π radians is 180 degrees
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\(\pi \quad radians\quad =\quad 180\quad degrees\\ \\ \frac { \pi \quad radians }{ 9 } =\frac { 180\quad degrees }{ 9 } \\ \\ \frac { \pi }{ 9 } \quad radians\quad =\quad 20\quad degrees\\ \\ 7\cdot \frac { \pi }{ 9 } radians=7\cdot 20\quad degrees\\ \\ \therefore \quad \frac { 7 }{ 9 } \pi \quad radians\quad =\quad 140\quad degrees\)