What is the length of s?

Answer:
s = 10[tex]\sqrt{2}[/tex]
Step-by-step explanation:
using the sine ratio in the right triangle and the exact value
sin45° = [tex]\frac{\sqrt{2} }{2}[/tex] , then
sin45° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{s}{20}[/tex] = [tex]\frac{\sqrt{2} }{2}[/tex] ( cross- multiply )
2s = 20[tex]\sqrt{2}[/tex] ( divide both sides by 2 )
s = 10[tex]\sqrt{2}[/tex]