Answer:
D
Step-by-step explanation:
Using the sine ratio in the right triangle
sin51° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{9}{y}[/tex] ( multiply both sides by y )
y × sin51° = 9 ( divide both sides by sin51° )
y = [tex]\frac{9}{sin51}[/tex] ≈ 11.6 ( to 1 dec. place ) → D
