find the measure of angle A

Answer:
Step-by-step explanation:
the sum of the interior angles of a triangle is 180°
180 - 70 = 110
110 = 12x + 2 + 15x
108 = 27x
108 : 27 = 4°
4 * 15 = 60° is your answer
check
15 * 4 + 12 * 4 + 2 + 70 = 180
60 + 48 + 72 = 180
the answer is good