Which equation can be used to find the length of AC

Answer:
the first one
Step-by-step explanation:
Since the triangle is right use the sine ratio to find AC
sin40° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{AC}{AB}[/tex]
sin40° = [tex]\frac{AC}{10}[/tex] ( multiply both sides by 10 )
10 sin40° = AC