Answer:
∠2 = 51°
Step-by-step explanation:
Supplementary angles sum to 180°, thus
11a + 19 + 6a - 9 = 180, that is
17a + 10 = 180 ( subtract 10 from both sides )
17a = 170 ( divide both sides by 17 )
a = 10
Hence
∠2 = 6a - 9 = (6 × 10) - 9 = 60 - 9 = 51°
