Answer:
∠A = 70°
Step-by-step explanation:
Since the sides of the isosceles triangle AB and AC are congruent then
The base angles B and C are congruent and ∠B = ∠C = 55°
The sum of the 3 angles in a triangle = 180°
Subtract the sum of angles B and C from 180 for angle A, that is
∠A = 180° - (55 + 55)° = 180° - 110° = 70°
