we know that
angle (3x) and angle (9x) are supplementary angles
so
3x+9x=180°------> 12x=180°------> x=180°/12-----> x=15°
angle (9x) and angle (1) are supplementary angles
so
9x+∡1=180---------> 9*15+∡1=180
∡1=180-9*15---------> ∡1=180-135------> ∡1=45°
the answer is
∡1 is 45°
alternative method
angle 1 = angle 3x----------> vertical angles
∡1=3x-----> 3*15-----> 45°
