Answer:
<h2>x = 3</h2>
Step-by-step explanation:

For this case we have to define trigonometric relations of rectangular triangles that:
- The cosine of an angle is given by the leg adjacent to the angle on the hypotenuse of the triangle.
- The sine of an angle is given by the leg opposite the angle on the hypotenuse of the triangle.
Then, according to the figure we have:

Answer:

Option D