Answer:
∠ q = 30°
Explanation:
given Δ pqr ≅ Δ stu , then
corresponding angles are congruent
that is ∠ p = ∠ s = 70°
the sum of the angles in Δ pqr = 180° , that is
∠ p + ∠ q + ∠ r = 180°
substitute ∠ r = 80° and ∠ p = 70°
70° + ∠ q + 80° = 180°
∠ q + 150° = 180° ( subtract 150° from both sides )
∠ q = 30°