Find the missing side x:

Probably 5

Step-by-step explanation:

This is an extremely confusing question.  Whoever wrote it most likely had a typo.

The little box in the corner of the triangle means that is 90 degrees. if that is the case, this is a simple question:

Apply pythagorean theorem (a^2 + b^2 = c^2)

In this case:

3^2 + 4^2 = x^2

x^2 = 25

x=5.

HOWEVER: the two given angles are 60 degrees and 50 degrees.

Which does not work. It creates an impossible triangle.