Answer:
option 3- 5 square root 2
Step-by-step explanation:
[tex]\sin 45° = \frac{BY}{OY} \\ \\ \frac{1}{ \sqrt{2} } = \frac{BY}{10} \\ \\ BY = \frac{10}{ \sqrt{2} } \\ \\ BY = \frac{10 \times \sqrt{2} }{ \sqrt{2} \times \sqrt{2} } \\ \\ BY = \frac{10 \sqrt{2} }{2 } \\ \\ \huge \red{ \boxed{BY = 5 \sqrt{2} }}[/tex]
