Answer:
m∠A = 70°
Explanation:
The dashes on line segments AB and AC mean that they are equal in length. Therefore, the triangle is an isosceles triangle. This means that the two base angles, ∠B and ∠C are congruent.
Interior angles of a triangle sum to 180°. Therefore:
⇒ m∠A + m∠B + m∠C = 180°
⇒ m∠A + 55° + 55° = 180°
⇒ m∠A + 110° = 180°
⇒ m∠A + 110° - 110° = 180° - 110°
⇒ m∠A = 70°