Answer:
∠ AMT = 78°
Explanation:
the diagonals of a rhombus bisect the angles , so
∠ HAT = ∠ HAM = 12° , then
∠ MAT = 12° + 12° = 24°
the sides of a rhombus are congruent , so AM = AT , thus
Δ MAT is isosceles with base angles congruent , that is
∠ AMT = ∠ ATM = (180 - 24)° ÷ 2 = 156° ÷ 2 = 78°