Answer:
Step-by-step explanation:
∠ 6=∠ 7
11 x+8=12 x-4
12 x-11 x=8+4
x=12
m∠6=11x+8=11×12+8=132+8=140°
m∠ 4+m∠ 6=180°
m∠4+140=180
m∠4=180-140=40°
