7.7. Consider the triangle $A B C$ with $A B=A C$ and $m(\angle B)>30^{\circ}$. Inside the triangle, we have a point $M$ such that $m(\angle M B C)=30^{\circ}$ and $m(\angle M A B)=\frac{3}{4} m(\angle B A C)$. Determine $m(\angle A M C)$.