Answer:
y = 10
Step-by-step explanation:
Using the sine ratio in the right triangle and the exact value
sin30° = [tex]\frac{1}{2}[/tex] , then
sin30° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{y}{20}[/tex] = [tex]\frac{1}{2}[/tex] ( cross- multiply )
2y = 20 ( divide both sides by 2 )
y = 10
