Step-by-step explanation:
[tex]sin \: 51 \degree = \frac{TV}{9} \\ \\ \therefore \: 0.77= \therefore \: \frac{TV}{9} \\ \\ \therefore \: TV = 0.77 \times 9 = 6.93 \\ \\ \therefore \: TV \approx \: 6.9[/tex]