Answer:
∠2 = 51°
Explanation:
The sum of supplementary angles = 180°
Equate the sum of the angles to 180 and solve for a
11a + 19 + 6a - 9 = 180
17a + 10 = 180 ( subtract 10 from both sides )
17a = 170 ( divide both sides by 17 )
a = 10
Hence
∠2 = (6 × 10) - 9 = 60 - 9 = 51°