Solution:
Given the right triangle below:
To solve for x, we use the trigonometric ratio.
In the above triangle, the angles at A and B are equal.
Thus, we have
[tex]\begin{gathered} \angle A+\angle B+\angle C=180(su\text{m of angles in a triangle\rparen} \\ \angle A=\angle B \\ thus, \\ 2\angle\text{B+90=180} \\ \Rightarrow2\angle\text{B=180-90} \\ 2\angle\text{B=90} \\ \Rightarrow\angle\text{B=45} \end{gathered}[/tex]
From trigonometric ratio,
[tex]\sin\theta\text{=}\frac{opposite}{hypotenuse}[/tex]
In this case, θ is the angle at B, which is 45; opposite is AC, and hypotenuse is AB.
Thus,
[tex]\begin{gathered} \sin45=\frac{x}{3\sqrt{2}} \\ \Rightarrow x=3\sqrt{2}\times\sin45 \\ =3\sqrt{2}\times\frac{1}{\sqrt{2}} \\ =3 \end{gathered}[/tex]
Hence, the value of x is
[tex]3[/tex]
The correct option is B
