So,
Given the triangle:
To find x, we could use a trigonometric equation.
Remember that the sine function relations the opposite side of a given angle, and the hypotenuse of the right triangle.
In this case, if we take 37° as our angle, the opposite side of it is x, and the hypotenuse is 12. Then,
[tex]\sin (37)=\frac{x}{12}[/tex]
So that's the equation that we could use to find the value of x.
