Step-by-step explanation:
Every triangle has 3 sides and 3 interior angles whose measures sum to 180 degrees. For example, a triangle with angles [tex]\theta[/tex], [tex]\alpha[/tex] and [tex]\beta[/tex]:
[tex]\theta+\alpha+\beta=180\º[/tex]
Following this rule, we will apply it to the angles XYZ, YXZ and the unknown XZY:
[tex]XYZ+YXZ+XZY=180\º[/tex]
[tex]50\º+75\º+XZY=180\º[/tex]
[tex]XZY=180\º-50\º-75\º[/tex]
Finally:
[tex]XZY=55\º[/tex]