Answer:
[tex]\large\boxed{m\angle S=78^o}[/tex]
Step-by-step explanation:
[tex]\text{If}\ \triangle MNP\cong\triangle QST,\ \text{then corresponding angles}\\\text{and corresponging sides are congruent.}\\\\\angle M\cong\angle Q\\\angle N\cong\angle S\\\angle P\cong\angle\\\\m\angle N=78^o,\ \text{therefore}\ m\angle S=78^o[/tex]
