Since the triangle in the diagram is a right triangle, we can use the trigonometric function cosine to solve this problem.
The cosine of an angle x is defined as follows:

First, we have to find the adjacent side to the angle x:
And then, find the hypotenuse of the triangle, which will be the side opposite to the 90° angle:

Thus, we substitute this in the definition of the cosine of x:

And to solve for x, we use the inverse cosine:

The result is:

Answer: 62.05°