Answer:
∠A = 24°
Explanation:
The exterior angle of a triangle is equal to the sum of the two opposite interior angles
∠D is an exterior angle of the triangle and a and B are the interior angles, hence
∠A + ∠B = ∠D, that is
∠A + 90 = 114 ( subtract 90 from both sides )
∠A = 114° - 90° = 24°