Answer:
RS ≈ 6.4
Step-by-step explanation:
Using the sine ratio in the right triangle
sin39° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{QR}{RS}[/tex] = [tex]\frac{4}{RS}[/tex] ( multiply both sides by RS )
RS × sin39° = 4 ( divide both sides by sin39° )
RS = [tex]\frac{4}{sin39}[/tex] ≈ 6.4 ( to the nearest tenth )
