We have an isosceles triangle. as XY = YZ, and mBoth mThen, we can use the fact that the sum of the measures of all internal angles is 180° and calculate m[tex]\begin{gathered} m\angle X+m\angle Y+m\angle Z=180\degree \\ 2m\angle Z+22=180 \\ 2m\angle Z=180-22 \\ 2m\angle Z=158 \\ m\angle Z=\frac{158}{2} \\ m\angle Z=79\degree \end{gathered}[/tex]Answer: m
